PTEN and colorectal carcinoma: There were only 4 out of 603 advanced CRC patients treated with capecitabine alone achieved CR in 2 phase III randomized clinical trials.[5,6] And in AVEX study, only 2 out of 140 patients treated with capecitabine achieved CR.[12] Maybe factors including mCRC with left-sided primary,[26] free of comorbidities and low mRNA expression of PTEN contribute to the great response to capecitabine and long-term survival.