BCL2 and cancer: It shall be mentioned, however, that in the Sv129 background the incidence of spontaneous cancer is increased, and lifespan is accordingly reduced (data not shown), unlike the crucial apoptosis inhibitors Bcl-2 and Bcl-XL whose overexpression does not promote cancer per se, except when it is confined in the B cell compartment (Frenzel et al., 2009; Pena et al., 1998).