MCL1 and neoplasm: In murine model systems of patient-derived orthotopic xenografts of human glioblastoma, breast cancer, and melanoma in vivo, and human glioblastoma U87MG, LN229, U251, T98G cells in vitro, the tumor growth can be degraded by the inhibition of histone deacetylase, mitochondrial matrix chaperones, and anti-apoptotic B-cell lymphoma 2 (Bcl-2) proteins including Bcl-2, Bcl-xL, and MCL-1 [19,21,22].