TP53 and gastric cancer: Given the importance of p53 loss in gastric cancer progression, the fact that PI3K/Akt activity directly favors p53 down-regulation by promoting Mdm2–mediated proteasomal degradation [37] posits enhanced Survivin expression as a potentially key determinant in gastric cancer progression by generating a feedback amplification loop that would not only promote PI3K/Akt activity, but also favor the loss of p53 and RPRM.