PIK3CA and neoplasm: Phosphorylated receptors then activate downstream signaling pathways such as Ras/MAPK, PI3K/AKT, PLC-γ and STAT [10], which regulate cellular processes under normal conditions but are associated with uncontrolled cellular activities due to aberrant ErbB signaling when receptors are overexpressed, ultimately leading to tumorigenesis and tumor growth [13].