Compounds that modulate the function of anti-apoptotic proteins such as Bcl-2 and related Bcl-2 family members are identified. These compounds have the ability to convert the activity of Bcl-2-family member proteins from anti-apoptotic to pro-apoptotic. Methods for inducing or preventing apoptosis are described, together with methods for identifying molecules that induce or prevent apoptosis through interaction with Bcl-2-family members. Methods for treatment of proliferative diseases and neurodegenerative diseases using the modulators of Bcl-2 and related family members are also disclosed.