PRTN3 and rheumatoid arthritis: We carried out a dose-ranging, double-blind, placebo-controlled phase I clinical trial of a single ascending dose of liposomes encapsulating 40 μg/mL CII + 400 ng/mL calcitriol (DEN-181) in 17 anti-citrullinated protein antibody+ (ACPA+) HLA-DRB1*0401 or *0101+ RA patients on methotrexate.