To elucidate whether Fas signaling determines the antitumor effects of endogenous TH9 cells, we reconstituted irradiated WT mice with Faslpr (Faslpr → WT) or WT (WT → WT) bone marrow cells and established tumors with Lewis lung carcinoma cells expressing full-length ovalbumin (LLC-OVA) in these mice. The gene discussed is FAS; the disease is Carcinoma, Lewis Lung.