Rullier et al. reported that the ratio of CK7(−)/CK20(+) was 4% in bile duct cancer, but 81% in colorectal cancer, and a combination of CK7 and CK20 is useful to determine that the ductal tumor was a metastatic lesion arising from colon cancer [2]. Here, KRT7 is linked to malignant colon neoplasm.