Additionally, the discovery of anti-cancer properties in molecules such as anti-microbial and cationic peptides [50,51], and the use of proteins of human origin such as pro-apoptotic Bax, Bak; granzyme B, TRAIL, FasL, C5a and RNAse [28,52,53] may pave the way for a future generation of antibody-based toxic proteins with clinical applications in cancer therapy. This evidence concerns the gene C5AR1 and cancer.