KLK1 and colorectal carcinoma: To gain insight into the effects of KLKs on the progression and prognosis of CRC, the present study investigated the expression profiles of KLKs in CRC using TCGA and GTEx databases and found that KLK1, KLK6, KLK8, KLK10, KLK11 and KLK12 were highly expressed in tumour tissues compared with normal tissues.