FAS and cancer: In order to construct gene products which: (1) induce synergistic apoptosis selectively in cancer cells with both mut Ras and p53; (2) activate both intrinsic and extrinsic pathway of apoptosis; and (3) retain the fail-safe mechanism utilizing the P14 gene to prevent activation in cells with low levels of wt p53, we evaluated the expression of a variety of pro-apoptotic genes with whole p14 including Bax, Bak, Fas, BID and truncated BID (tBID).