SH-E4A-66 is a C 2 -COUPLr (COvalent Protein Ligator) with carbazole scaffold barring heterogeneous cysteine reactive warheads (acrylamide and chloroacetamide). SH-E4A-66 is capable of coupling with EML4-ALK ( EC 50 =1.5 μM) and inhibiting the activity of EML4-ALK kinase ( IC 50 =2.3 µM).