The therapeutic potential of the complement system as an anti-cancer agent was translated in the clinical practice, where a phase I trial (STELLAR-001) has been designed to investigate IPH5401 (anti-C5aR) in combination with durvalumab (anti-PD-1) in advanced solid tumors (NCT03665129, https://clinicaltrials.gov/ct2/show/NCT03665129) (140). This evidence concerns the gene C5AR1 and cancer.