PIK3CA and malignant colon neoplasm: Proximal colon cancers usually exhibit a CIMP-H and MSI-H phenotype and are more often mutated in BRAF and PIK3Ca, whereas distal colon cancers more often exhibit chromosomal instability (CIN), mutations in KRAS, APC, and p53, and the amplification of HER1 and HER2 genes [140,141].