Cebpd plays an important role in CIA mice.

A, Age- and sex-matched C57BL/6 mice were immunized with chicken CII emulsified in CFA at day 0. The mice were scored every 2–3 days without knowledge of their genotypes. Clinical score of arthritis: the scores for four paws were obtained for each mouse, and the total severity score for the group was divided by the number of animals in the group to obtain an average severity score. B, The rear paws and joints from Cebpd^+/+ and Cebpd^−/− mice were stained with hematoxylin and eosin after collagen-induced arthritis. C, Histopathological scores: the score from two ankle joints in each mouse was assessed by two orthopedic surgeons blind to the genotypes of the mice. The average histopathological score in the Cebpd ^−/− group was significantly lower than that of the wild-type group (p = 0.016). *p<0.05; n = 10 for control and n = 6 for the experimental group.