For testing whether ACPAs are involved in the TNF-α production by macrophages, Clavel et al. [17] developed an in vitro human model in which monocyte-derived macrophages were incubated with ACPA-containing immune complex (ACPA-ICs) generated by mixing RA-derived ACPA and citrullinated fibrin-derived peptides. The gene discussed is PRTN3; the disease is rheumatoid arthritis.