We have shown previously that the helical domain mutations E542K and E545K are by far the most common mutations found in PIK3CA in bladder cancer [4] and are more potent than H1047R in inducing signaling downstream of AKT and proliferation at confluence and under conditions of nutrient depletion when expressed in normal urothelial cells [29]. Here, PIK3CA is linked to urinary bladder carcinoma.