Clinical symptoms of CIA in collagen-injected CA1-Tg mice. The incidence of arthritis (A), clinical scores (B) and hind-paw thicknesses (C) were measured in CA1-Tg mice (filled squares, n = 10), PADI4-Tg mice (filled circles, n = 10) and wild-type (empty triangle, n = 10) mice at different time points after the first injection of collagen. CA1-Tg mice that received BSA were also included as a control (empty circles, n = 10). (D) Evident CIA appeared in the hind paws of CA1-Tg mice. a The collagen-injected CA1-Tg mice on the 35th day after the first injection of collagen, b collagen-injected CA1-Tg mice on the 77th day, c collagen-injected CA1-Tg mice on the 92nd day, d BSA-treated CA1-Tg mice on the 77th day, e collagen-injected PADI4-Tg mice on the 77th day, and f collagen-injected wild-type mice on the 77th day.