CCR1 and neoplasm: Once activated by the infiltration of immune cells, these fibroblasts produce pro-inflammatory chemokines such as CXCL1 and CXCL2 through the recruitment of tumour-associated macrophages in primary tumours [65], while CCL5 being secreted by these fibroblasts recruits tumour-infiltrating regulatory T cells by signalling through the CCR1 receptor expressed in these cells [66].