The DPEP2 expression in tumor-resident monocytes/macrophages from colorectal tumor tissues and ovarian serous cystadenocarcinoma tissues was much higher than that in other immune cells (Fig. 2E, F), whereas we did not find increased expression of DPEP1 or DPEP3 in tumor-resident macrophages, which demonstrated the potential function of DPEP2, independent of its dipeptidase activity in macrophages (Fig. S2A–D). Here, DPEP2 is linked to colorectal neoplasm.