We also investigated the expression of HTRA1 in normal colon cells and seven different CRC cell lines, and found that HTRA1 was highly expressed in DLD1, HCT8, and SW620 cells compared with normal human colonic epithelial NCM460 cells at both transcriptional and translational levels (Fig. 1F, G). Here, HTRA1 is linked to colorectal carcinoma.