CD4 and melanoma: Tumor regression in melanoma-bearing Nlrp3-/- mice was accompanied by significantly increased frequencies of tumor-infiltrating CD45+ leukocytes (Figure 2C), CD8+ lymphocytes, which exhibited elevated IFN-γ expression, and NK1.1+ cells, as well as increased frequencies of CD4+ T cells, compared to WT mice (Figures 2D, E).