In mice, ILC2s in advanced CRC highly express Hs3st1 (encodes the effector product that catalyzes heparan sulfate biosynthesis) and Pdcd1 (encodes immune checkpoint PD-1); deficiency of PD1 or HS3ST1 in murine ILC2s can considerably inhibit CRC tumor proliferation (71). Here, PDCD1 is linked to neoplasm.