PIK3CA and cancer: FN1, a high molecular weight (~440 kDa) ECM cell-adhesive glycoprotein, is predominantly expressed in various cancer tissues but not in normal tissues [49] and involved in the ECM-receptor interaction, focal adhesion pathway, pathways in cancer, and the regulation of endothelial cell survival, proliferation, adhesion, migration, inflammation, and angiogenesis through the activation of the focal adhesion kinase (FAK) and downstream PI3K/Akt signalling pathways, as well as the activation of NF-κB [50, 51].