WNT5A and Arthritis: In contrast, Wnt5a stimulates ossification marker expression in cultured osteoblasts and increases the tibial plateau bone volume in cultured explants of mouse ankle.61 Wnt5a is also involved in arthritis development by promoting osteoclast activity and the inflammation response.62 Wnt5a conditional knockout mice are resistant to the development of arthritis compared with control littermates, providing more insight into the role of endogenous Wnt5a in autoimmune diseases.62