Evidence suggests that activating mutations in PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha) and deletion of PTEN drive the accumulation of myeloid-derived suppressor cells (MDSCs) in CRC through GM-CSF signaling, thereby facilitating immune evasion. This evidence concerns the gene PIK3CA and colorectal carcinoma.