CD4 and neoplasm: Due to the GSEA-indicated enrichment in gene sets associated with CD4 + T cell activation, lymphocyte activation, and leukocyte proliferation in Braf/Pten/Cxcr2−/− tumors (Fig. 2D), we then evaluated the immune cell infiltrate between Braf/Pten/Cxcr2WT and Braf/Pten/Cxcr2−/− tumor-bearing mice.