Narimatsu’s team [23] performed a combined detection of CA19‐9/DU‐PAN‐2 (a cell antibody that is overexpressed in tumor cells and was used for cancer marker detection in the past) on 15 Lewis‐negative colorectal cancer patients, and the results showed that serum CA19‐9 levels were all less than 1.0 unit/mL while another tumor marker DU‐PAN‐2 level exceeded the cutoff value, and even 7 patients had results far higher than Lewis‐positive control group patients. This evidence concerns the gene PAN2 and neoplasm.