However, no significant difference was observed in tumor growth between tumor-bearing Id2fl/flCd4-Cre+ mice treated with the anti-PD-1 antibody and those treated with control IgG, mainly due to the decreased population of Slamf6+ Texprog cells that can respond to PD-1 blockade (Fig. 6K). The gene discussed is PDCD1; the disease is neoplasm.