Novel polypeptides having anti-apoptotic activity, and methods of screening for such novel polypeptides having anti-apoptotic activity, and polynucleotides encoding such polypeptides; Compounds that regulate or modulate apoptosis and/or anti-apoptotic activity, such as compounds having anti-apoptotic activity, and such as compounds that induce, restore, or modulate apoptosis and/or inhibit, diminish, or modulate anti-apoptotic activity, methods of screening for such compounds, and methods of using such compounds in the therapeutic treatment of diseases; Methods of treating eukaryotic cells with compounds that regulate or modulate apoptosis and/or anti-apoptotic activity; Methods of enhancing the stability, growth, and/or productivity of eukaryotic cells; Pharmaceutical compositions that regulate or modulate apoptosis and/or anti-apoptotic activity.