PIK3CA and cancer: Among gene mutations and alterations, key mutations which are responsible for cancer progression such as mutations in CDC27, BCLAF1, and AQP7,30 common oncogenic mutations such as PIK3CA, TP53, and FGFR3 and TP53,36 Copy number variations (CNVs) and loss of heterozygosity (LOH) in CASP8, RASA1, and NOTCH genes55 and Microsatellite instability (MSI) and genetic instability54 were reported.