Similarly to ritanserin, DGKζ-IN-4 reduced cell viability in some of the selected AML models, with HL-60 being the most sensitive (IC50 = 21 μM), followed by THP-1 (IC50 = 31 μM) and HEL (IC50 = 51 μM), while K562 showed no detectable cytotoxic effects across the tested concentration range at 24 h and mild sensitivity after prolonged exposure (IC50 = 33 μM at 72 h). This evidence concerns the gene DGKZ and acute myeloid leukemia.