000100 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 010000 - Statement - CONSOLIDATED BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 010100 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 020000 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS link:presentationLink link:calculationLink link:definitionLink 030000 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) link:presentationLink link:calculationLink link:definitionLink 040000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS link:presentationLink link:calculationLink link:definitionLink 060100 - Disclosure - ORGANIZATION AND DESCRIPTION OF BUSINESS link:presentationLink link:calculationLink link:definitionLink 060200 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES link:presentationLink link:calculationLink link:definitionLink 060300 - Disclosure - BUSINESS COMBINATION link:presentationLink link:calculationLink link:definitionLink 060400 - Disclosure - ACQUISITION link:presentationLink link:calculationLink link:definitionLink 060500 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS link:presentationLink link:calculationLink link:definitionLink 060600 - Disclosure - PROPERTY AND EQUIPMENT, NET link:presentationLink link:calculationLink link:definitionLink 060700 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES link:presentationLink link:calculationLink link:definitionLink 060800 - Disclosure - NOTES PAYABLE link:presentationLink link:calculationLink link:definitionLink 060900 - Disclosure - LEASES link:presentationLink link:calculationLink link:definitionLink 061000 - Disclosure - CONVERTIBLE PREFERRED STOCK link:presentationLink link:calculationLink link:definitionLink 061100 - Disclosure - STOCKHOLDERS' EQUITY (DEFICIT) link:presentationLink link:calculationLink link:definitionLink 061200 - Disclosure - EQUITY INCENTIVE PLAN link:presentationLink link:calculationLink link:definitionLink 061300 - Disclosure - NET LOSS PER SHARE link:presentationLink link:calculationLink link:definitionLink 061400 - Disclosure - WARRANT LIABILITIES link:presentationLink link:calculationLink link:definitionLink 061500 - Disclosure - INCOME TAXES link:presentationLink link:calculationLink link:definitionLink 061600 - Disclosure - RELATED PARTY TRANSACTIONS link:presentationLink link:calculationLink link:definitionLink 061700 - Disclosure - COMMITMENTS AND CONTINGENCIES link:presentationLink link:calculationLink link:definitionLink 070200 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) link:presentationLink link:calculationLink link:definitionLink 080200 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) link:presentationLink link:calculationLink link:definitionLink 080400 - Disclosure - ACQUISITION (Tables) link:presentationLink link:calculationLink link:definitionLink 080500 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables) link:presentationLink link:calculationLink link:definitionLink 080600 - Disclosure - PROPERTY AND EQUIPMENT, NET (Tables) link:presentationLink link:calculationLink link:definitionLink 080700 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables) link:presentationLink link:calculationLink link:definitionLink 080900 - Disclosure - LEASES (Tables) link:presentationLink link:calculationLink link:definitionLink 081000 - Disclosure - CONVERTIBLE PREFERRED STOCK (Tables) link:presentationLink link:calculationLink link:definitionLink 081200 - Disclosure - EQUITY INCENTIVE PLAN (Tables) link:presentationLink link:calculationLink link:definitionLink 081300 - Disclosure - NET LOSS PER SHARE (Tables) link:presentationLink link:calculationLink link:definitionLink 081500 - Disclosure - INCOME TAXES (Tables) link:presentationLink link:calculationLink link:definitionLink 090200 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Investments in Marketable Securities (Details) link:presentationLink link:calculationLink link:definitionLink 090202 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Property and Equipment, net (Details) link:presentationLink link:calculationLink link:definitionLink 090204 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Leases (Details) link:presentationLink link:calculationLink link:definitionLink 090206 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Impairment of Long-Lived Assets (Details) link:presentationLink link:calculationLink link:definitionLink 090208 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Sales and Marketing (Details) link:presentationLink link:calculationLink link:definitionLink 090210 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Stock-Based Compensation (Details) link:presentationLink link:calculationLink link:definitionLink 090212 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Income Taxes (Details) link:presentationLink link:calculationLink link:definitionLink 090214 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Warrant Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 090300 - Disclosure - BUSINESS COMBINATION (Details) link:presentationLink link:calculationLink link:definitionLink 090400 - Disclosure - ACQUISITION (Details) link:presentationLink link:calculationLink link:definitionLink 090500 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) link:presentationLink link:calculationLink link:definitionLink 090600 - Disclosure - PROPERTY AND EQUIPMENT, NET (Details) link:presentationLink link:calculationLink link:definitionLink 090700 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) link:presentationLink link:calculationLink link:definitionLink 090800 - Disclosure - NOTES PAYABLE (Details) link:presentationLink link:calculationLink link:definitionLink 090900 - Disclosure - LEASES, Lease Terms (Details) link:presentationLink link:calculationLink link:definitionLink 090902 - Disclosure - LEASES, Lease-Related Costs (Details) link:presentationLink link:calculationLink link:definitionLink 090904 - Disclosure - LEASES, Other Information Related to Leases (Details) link:presentationLink link:calculationLink link:definitionLink 090906 - Disclosure - LEASES, Future Minimum Lease Payments Under Non-Cancellable Leases (Details) link:presentationLink link:calculationLink link:definitionLink 090908 - Disclosure - LEASES, Rent Expense Prior to Adoption of Topic 842 (Details) link:presentationLink link:calculationLink link:definitionLink 090908 - Disclosure - LEASES, Future Minimum Lease Payments Under Non-Cancellable Leases (Details) Calc 2 link:presentationLink link:calculationLink link:definitionLink 091000 - Disclosure - CONVERTIBLE PREFERRED STOCK (Details) link:presentationLink link:calculationLink link:definitionLink 091100 - Disclosure - STOCKHOLDERS' EQUITY (DEFICIT) (Details) link:presentationLink link:calculationLink link:definitionLink 091200 - Disclosure - EQUITY INCENTIVE PLAN, Stock Option Activity (Details) link:presentationLink link:calculationLink link:definitionLink 091202 - Disclosure - EQUITY INCENTIVE PLAN, Assumptions Used to Value Option Grants (Details) link:presentationLink link:calculationLink link:definitionLink 091204 - Disclosure - EQUITY INCENTIVE PLAN, Restricted Stock Unit Activity (Details) link:presentationLink link:calculationLink link:definitionLink 091206 - Disclosure - EQUITY INCENTIVE PLAN, Stock-Based Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 091300 - Disclosure - NET LOSS PER SHARE (Details) link:presentationLink link:calculationLink link:definitionLink 091400 - Disclosure - WARRANT LIABILITIES (Details) link:presentationLink link:calculationLink link:definitionLink 091500 - Disclosure - INCOME TAXES, Effective Income Tax Rate Reconciliation (Details) link:presentationLink link:calculationLink link:definitionLink 091502 - Disclosure - INCOME TAXES, Deferred Tax Assets (Liabilities) (Details) link:presentationLink link:calculationLink link:definitionLink 091504 - Disclosure - INCOME TAXES, Tax Net Operating Loss Carryforwards and Tax Credit Carryforwards (Details) link:presentationLink link:calculationLink link:definitionLink 091600 - Disclosure - RELATED PARTY TRANSACTIONS (Details) link:presentationLink link:calculationLink link:definitionLink 091700 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details) link:presentationLink link:calculationLink link:definitionLink