C5AR1 and ovarian benign neoplasm: The sensitivity and specificity of serum CA125, serum sEV CA125, HE4, C5a, and their combination (OCS) for differentiating between benign and non-benign ovarian tumors were as follows: serum CA125 sensitivity was 75%, specificity was 66.8%; serum sEV CA125 sensitivity was 61.4%, specificity was 96.3%; HE4 sensitivity was 77.3%, specificity was 73.7%; C5a sensitivity was 68.2%, specificity was 77.9%; OCS sensitivity was 77.3%, and specificity was 93.2%.