CCR1 and cancer: Previous studies have shown that myeloid-derived suppressor cells (MDSCs) [28], tumor-infiltrating lymphocytes (TIL) [29], MSCs [8], CAFs [26] and CSLCs [14] can produce CCL5 and that cancer cells express the CCL5 receptors CCR1, CCR3, and CCR5 [14, 26,30].