Therefore, given the dominating role of PI3K/AKT signaling in cell survival mechanisms and the association of XIAP and survivin in cancer progression [5], we posited that loss of TGFβ signaling may contribute to enhanced XIAP/survivin expression and consequently loss of TGFβ signaling may be a key to an aberrant survival mechanism permitting metastatic growth at distal organ sites in contrast to the current view that TGFβ TSG is primarily a gatekeeper to prevent oncogenesis. This evidence concerns the gene XIAP and cancer.