Furthermore, C5aR was reported to be overexpressed in a variety of tumors, including non-small cell lung cancer (NSCLC) [12–14], gastric cancer (GC) [15, 16], hepatocellular carcinoma (HCC) [17], urothelial cell carcinoma (UCC) [18], prostate cancer (PC) [19], renal cell carcinoma (RCC) [20, 21], and breast cancer (BC) [22]. This evidence concerns the gene C5AR1 and breast cancer.