PIK3CA and cancer: Additionally, signaling pathways such as PD-L1 (Programmed death ligand 1), apoptosis, IL-17 (Interleukin 17), TNF, MAPK (mitogen-activated protein kinase), RAS, VEGF (vascular endothelial growth factor), PI3K-Akt, the cell cycle, p53, Wnt and NOTCH could be functionally altered by the downstream targeting of HOX proteins on critical cancer-associated genes during oral carcinogenesis (Fig. 7d–f).