Erlotinib HCl (formerly OSI-744, OSI744; trade name: Tarceva), the hydrochloride salt of erlotinib, is an EGFR (epidermal growth factor receptor) inhibitor with antitumor activity. In cell-free experiments, it inhibits EGFR with an IC50 of 2 nM, and when compared to human c-Src or v-Abl, it is >1000 times more sensitive to inhibit EGFR. The FDA and other nations have authorized erlotinib, a quinazoline derivative, for the treatment of pancreatic cancer, non-small cell lung cancer (NSCLC), and various other cancer types.