PIK3CA and colorectal carcinoma: In fact, there were three cases with mutations in both KRAS and PIK3CA among our panel (CRC-017T: KRAS G13D, PIK3A Q546K, TP53 R81X and P27R; CRC-021T: KRAS G13D); however, they could not be used for in vivo validation due to the difficulty in obtaining sufficient PDX cells for in vivo combination efficacy test.