PIK3CA and cancer: In different cancers, the noncanonical pathway includes the activation of various pathways, such as the PCP/Rho/Jun-N-terminal kinase (JUN), receptor tyrosine kinase (RTK) (PI3K/AKT and YAP/TAZ signaling), or Ca2+ signaling cascades activated via the Frizzled ((Fz), as in the canonical pathway), ROR1/ROR2, or RYK receptors.