PIK3CA and colorectal carcinoma: High concordance was present in driver mutations such as APC, KRAS, NRAS, PIK3CA and SMAD4, in addition to AMER1, TCF7L2, CARD11 and the EGFR family members EGFR and ERBB3. Our analysis indicates that gene CNVs are the major source of tumour heterogeneity in CRC development.