Thus, even though monocytic AML cell differentiation is associated with differences in responsiveness to certain targeted therapies (e.g., Bcl-2, BET, CDK4/6, and possibly proteasomal inhibitors), and this seems to at least partly be due to common metabolic characteristics [22,93], our present study demonstrates that FAB-M4/M5 patients also show a proteomic heterogeneity with regard to fundamental cellular functions. The gene discussed is CDK4; the disease is acute myeloid leukemia.