The aim of the study was to evaluate the expression of five key genes encoding the proteins included in the PI3K/AKT signaling pathway, namely PIK3CA (encoding the catalytic subunit of PI3K), PTEN, AKT1 (encoding AKT kinase), FOXO1, and FRAP (encoding mTOR kinase), in relation to two reference genes: GAPDH and ACTB in patients with CRC. The gene discussed is PIK3CA; the disease is colorectal carcinoma.