Finally, the investigation of 162 samples by Laurent-Puig and colleagues reported the PTEN null expression rate of 19.9% with an association of poorer OS in the KRAS wild-type population (p = 0.013) but not with tumor response or PFS, thus suggesting the PTEN loss of expression as a prognostic rather than a predictive role (53). This evidence concerns the gene PTEN and neoplasm.