For instance, Jackson et al. [65] reported that C3 promotes the onset and growth of cutaneous squamous cell carcinomas (cSCCs) independent of C3aR1 and C5, while de Visser et al. reported that tumor immune infiltration and tumorigenesis of HPV-driven SCC are independent of the C3 pathway [71]. Here, C3AR1 is linked to cutaneous squamous cell carcinoma.