Tumor promoter exposure in these mice leads to elevated levels of C-X-C motif chemokine ligand 5 (CXCL5) and macrophage colony-stimulating factor (M-CSF), promoting the accumulation of CD200R+ MDSCs and forkhead box P3 (FoxP3+) regulatory T cells while reducing activated CD4+ T cells in the skin [17]. Here, CD4 is linked to neoplasm.