PIK3CA and cancer: In most cancers, the earliest acquired hallmark function might be evading apoptosis because the majority of first mutated genes in every cancer type in Table 3 (TP53, APC, KRAS, PIK3CA, NPM1 and CIC) have been found to encode apoptosis-regulating proteins, and the mutation of all of these genes has been shown to lead to deficient apoptosis functions.