Bufalin is cardioactive steroid that exhibits a variety of biological activities, such as cardiotonic, anaesthetic, blood pressure stimulatory, respiratory and antineoplastic effects. Acts as a specific Na⁺/K⁺-ATPase inhibitor. More potent than ouabain. Induces cell differentiation. Induces apoptosis in U937 and HL-60 cells by activation of AP-1 via a MAPK pathway that involves JNK. Regulates Tiam1 gene. Down regulates expression of 14-3-3 protein.