Mitochondrial regulation relapsed or refractory AML cells. A. Venetoclax inhibits anti-apoptotic protein BCL-2, which leads to increased cytochrome C release and induction of intrinsic apoptosis in sensitive cells. B. In resistant relapsed or refractory AML cells, increased expression of anti-apoptotic proteins (MCL1, BCL-xL) leads to a decrease in intrinsic apoptosis. C. In relapsed or refractory AML cells resistant to venetoclax, increased oxidative phosphorylation can be supported by amino acid uptake, beta oxidation of fatty acids, and nicotinamide adenine dinucleotide (NAD+) synthesis.