The largest study (total N = 1427; 170 MSI-high cancers) by Samowitz et al. [22] showed no prognostic role of TGFBR2 or BAX mutations among MSI-high colorectal cancer cases, in agreement with our current study - the second largest study to date and the only study which examined other key tumor molecular biomarkers such as CIMP, LINE-1 methylation and KRAS, BRAF and PIK3CA mutations. This evidence concerns the gene PIK3CA and colorectal cancer.