PIK3CA and neoplasm: Many of the signal transduction pathways that regulate the tumor microenvironment, including Ras/Raf/MAPK, Raf/JNK, Rho/Rac/PAK, and PI3K/Akt/mTOR, are convergent downstream signaling pathways of RTKs, implicating their role in GBM invasiveness and aggressiveness [76].