BCL2 and small cell lung carcinoma: Through SCLC and several lymphoid malignancies, navitoclax can be well-explained to have an effect through the inhibition of either BCL-2, BCL-W or BCL-XL activities, with MCL-1 expression having minor influence However, further downstream signaling of the intrinsic apoptotic pathway through BCL-2 family members is modulated by the expression of proapoptotic activators such as BIM, and executioner proteins as well.