CD44 and digestive system neoplasm: Generally, group 1 ILCs are associated with antitumor properties, including direct cytotoxicity13 and high expression of antitumor cytokines including IFN‐γ, perforin, and granzyme B.7, 13, 26, 32, 33Compared with normal adjacent tissue, a higher frequency of activated tumor protective hILC1s, marked by expression of high levels of CD69 and CD44,34 were described in gastrointestinal tumors.