IL33 and neoplasm: Importantly, removing the PD-1 ectodomain from the PD-1–IgG4 decoy neither impacted tumor control by IL-2v/IL-33-transduced OT1 cells (Fig. 5b) nor impaired the accumulation of PD-1+Gzmc+TCF1neg OT1 TILs (Fig. 5c).