IL2 and neoplasm: This indicated that the increase of tumor‐infiltrating cytotoxic lymphocytes via the localized IL‐2 delivery of FPC2‐IG‐IL‐2 may not be effective enough to elicit antitumor immune responses compared to that of PEGylated IL‐2, which was reported to promote the proliferation and activation of T and NK cells not only within tumors but also within the peripheral blood.34