MYCMI-6 (NSC354961) is a potent and selective endogenous MYC:MAX protein interactions inhibitor. MYCMI-6 blocks MYC-driven transcription and binds selectively to the MYC bHLHZip domain with a Kd of 1.6?μM. MYCMI-6 inhibits tumor cell growth in a MYC-dependent manner (IC50<0.5?μM). MYCMI-6 is not cytotoxic to normal human cells. MYCMI-6 induces apoptosis.