FAP and neoplasm: Hence, similar with the HDL-C, the lower level of plasma FAPα in cancer patients could possibly be a phenomenon comparable to decreased plasma level of acute-phase proteins discovered in inflammatory processes and malignancy (e.g., low plasma levels of transferrin, albumin, and inter-alpha-trypsin inhibitors) [8], or related to other speculated processes, such as the organ function decline and muscle mass consumption, which indicated the plasma FAPα was a negative acute-phase protein in response to tumor.