C5AR1 and neoplasm: In OC, it has been observed that C5aR1 independently predicts poor prognosis and correlates with the infiltration of immunosuppressive cells within the tumor microenvironment, characterized by increased infiltration of pro-tumor cells (Treg cells, M2 polarized macrophages, and neutrophils) and impaired CD8+ T cell function, leading to poor responses to immune checkpoint inhibitors (ICIs) 26.