In a previous study, we documented the early downregulation of Mcl-1 induced by UNBS1450 in the hematopoietic cancer cells.19 Here, we demonstrate that cardenolides (ouabain, digitoxin, digoxin) or bufadienolides (cinobufagin and proscillaridin A) similarly modulate Mcl-1. The gene discussed is MCL1; the disease is hematopoietic and lymphoid cell neoplasm.