Erlotinib-13C6 (CP-358774-13C6) is a 13C-labeled Erlotinib. Erlotinib is a directly acting EGFR tyrosine kinase inhibitor, with an IC50 of 2 nM for human EGFR[1].

Erlotinib effectively diminishes EGFR autophosphorylation in intact tumor cells, presenting an IC50 value of 20 nM, and is employed in treating non-small cell lung cancer[1]. Additionally, stable heavy isotopes of hydrogen, carbon, and other elements are integrated into drug molecules, primarily serving as tracers for quantification throughout drug development[2].