[{"from": "human", "value": "Could you provide a description of this molecule? [C][N][C][=C][Branch1][O][C][=C][C][=C][C][=C][Ring1][=Branch1][Ring1][=Branch2][C][=N][C][=Branch1][=Branch1][=N][C][=C][Ring1][=Branch1][N][C][=C][Branch2][Ring1][=N][C][=C][Branch1][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][N][C][=Branch1][C][=O][C][=C][N][Branch1][C][C][C][C][N][Branch1][C][C][C][O][C].[C][S][=Branch1][C][=O][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is the mesylate salt form of osimertinib, a third-generation, orally available, irreversible, mutant-selective, epidermal growth factor receptor (EGFR) inhibitor, with potential antineoplastic activity. Upon oral administration, osimertinib covalently binds to and inhibits the activity of numerous mutant forms of EGFR, including the secondarily-acquired resistance mutation T790M, L858R, and exon 19 deletions, thereby preventing EGFR-mediated signaling. This may both induce cell death and inhibit tumor growth in EGFR-overexpressing tumor cells. EGFR, a receptor tyrosine kinase mutated in many tumor cell types, plays a key role in tumor cell proliferation and tumor vascularization. As this agent is selective towards mutant forms of EGFR, its toxicity profile may be reduced when compared to non-selective EGFR inhibitors which also inhibit wild-type EGFR."}]