BCL2 and cancer: cFLIPS, FLICE-like inhibitory proteins; IAPs, inhibitors of apoptosis proteins; Bcl-2, Bcl-2 family proteins; ABC, ATP-binding efflux multidrug resistance transporters; HIF-1, hypoxia-inducible factor 1; IL-4, interleukin-4; NF-κB, nuclear factor-κB are suggested to modulate CSCs resistance to death and cancer therapies.