PIK3CA and colorectal carcinoma: Mutations in PIK3CA have been identified as the driver for many cancers in asymptomatic patients (those without phenotypes related to PIK3CA abnormalities), with common cancer types including breast (>30%), endometrial (>30%), bladder (>20%), colorectal carcinoma (>17%), and head and neck squamous cell carcinoma (>15%) (23).