Here we report quantification of levels of the PIK3CA E545K and H1047R hotspot point mutations in normal colonic mucosa, colonic adenocarcinomas, normal lung, and lung adenocarcinomas, as well as levels of the PIK3CA E545K mutation in normal breast, mammary ductal carcinoma, normal thyroid, and papillary thyroid carcinoma (PTC). Here, PIK3CA is linked to differentiated thyroid carcinoma.