ORGANIZATION AND DESCRIPTION OF BUSINESS	9 Months Ended
ORGANIZATION AND DESCRIPTION OF BUSINESS	Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND DESCRIPTION OF BUSINESS	ORGANIZATION AND DESCRIPTION OF BUSINESS GRAIL, Inc. (“GRAIL” or the “Company”), headquartered in Menlo Park, California, is an innovative commercial-stage healthcare company focused on saving lives and shifting the paradigm of early cancer detection. The Company’s Galleri blood test is a commercially available screening test for early detection of multiple types of cancer. GRAIL’s common stock is listed under the ticker symbol “GRAL” on the Nasdaq Stock Exchange. GRAIL was previously acquired by Illumina, Inc. (”Illumina”) in August 2021, at which point it became a 100% owned subsidiary of Illumina, and held separate as a part of binding hold separate commitments implemented pursuant to orders issued by the European Commission (the “Acquisition”). GRAIL separated from Illumina on June 24, 2024, as described below. GRAIL was a limited liability company (“LLC”) from August 19, 2021 to June 21, 2024 when it was converted into a corporation (the “Conversion”) in anticipation of such separation. Separation from Illumina On June 24, 2024, (the “Distribution Date”), Illumina completed the previously announced spin-off of GRAIL (the “Spin-Off”). The Spin-Off was completed through a distribution of 85.5% of the Company’s outstanding common stock to the holders of record of Illumina’s common stock as of the close of business on June 13, 2024 (the “Distribution”), which resulted in the distribution of 31.0 million shares of common stock. As a result of the Distribution, the Company became an independent public entity. Illumina’s ownership of GRAIL reduced to 4,502,126 shares of common stock representing 14.5% ownership of the Company after the Spin-Off. Unless the context otherwise requires, references to the “Company” or “GRAIL”, refer to (i) GRAIL, LLC prior to the Conversion and (ii) GRAIL, Inc. and its subsidiaries following the Conversion. In connection with the Spin-Off, the Company entered into or adopted agreements that provide a framework for the relationship between the Company and Illumina, including, but not limited to the following: •Separation and Distribution Agreement — governed the terms and conditions of the Spin-Off and sets forth aspects of the Company’s and Illumina’s relationship following the Spin-Off. See Note 9 — Legal And Regulatory Proceedings for more information regarding the contingencies related to this agreement. •Tax Matters Agreement — governs the respective rights, responsibilities and obligations of Illumina and the Company after the Spin-Off with respect to all tax matters and includes restrictions to preserve the tax-free status of the Distribution. See Note 12 — Taxes for more information regarding income taxes and Note 9 — Legal And Regulatory Proceedings regarding the contingencies related to this agreement. •Employee Matters Agreement — addressed employment, compensation, and benefits matters, including the allocation and treatment of assets and liabilities relating to employees and compensation and benefits plans and programs in which GRAIL employees participate, as well as the treatment of cash-based incentive awards in connection with the Spin-Off. See Note 8 — Stock-Based Compensation for further details regarding the treatment of equity awards. •Stockholder and Registration Rights Agreement — governs the respective rights, responsibilities and obligations of Illumina and the Company after the Spin-Off with respect to Illumina’s continuing ownership of GRAIL common stock. •Supply and Commercialization Agreement Amendment — amended the Company’s supply and commercialization agreement with Illumina, which governs the ongoing supply and commercial relationship, including licensing, royalty payments and intellectual property between GRAIL and Illumina. See Note 14 — Related Party Transactions for more information regarding the royalty arrangements with Illumina. Illumina provided the Company with disposal funding (the “Disposal Funding”) in the amount of $932.3 million in accordance with the Separation and Distribution Agreement, which was subject to a clawback feature that lapsed on September 24, 2025. See Note 9 — Legal And Regulatory Proceedings — Contingencies for details. Our Ability to Continue as a Going Concern The accompanying unaudited condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The realization of assets and the satisfaction of liabilities in the normal course of business are dependent on, among other things, the Company’s ability to manage its net loss and to become profitable and operate profitably, to manage the Company’s negative cash flows from operations and to generate positive cash flows from operations, and the Company’s ability to obtain financing to support working capital requirements. The Company had $126.9 million of cash and cash equivalents and $413.2 million of short-term marketable securities as of September 30, 2025. The Company believes that its existing cash, cash equivalents, and short-term marketable securities will be sufficient to meet its working capital and capital expenditure needs for at least the next 12 months, as of the date these unaudited condensed consolidated financial statements were filed.