PIK3CA and colorectal carcinoma: In the same study, the multivariate analysis observed a high risk of death of CRC KRAS exon 3 or 4 mutated patients compared to exon 2 KRAS mutations with PIK3CA bi-mutation (univariate Hazard Ratio (HR) = 8.05; 95% confidence interval (CI): 1.926–33.64, p = 0.004; multivariate HR = 10.505; 95% CI: 2.304–47.905, p = 0.002) [147].