Although ibrutinib was largely inactive as a single agent in the tested AML cells, we successfully sensitized two of the more resistant AML cell lines (TEX, IC50 = 13.01 μM and OCI-AML2, IC50 = 27.44 μM) to ibrutinib by combining the drug with the putative PARG inhibitor ethacridine. The gene discussed is PARG; the disease is acute myeloid leukemia.