IPA analysis indicated the top pathways downregulated in WNK2− chondrocytes cultured in isotonic conditions are those associated with OA, the role of chondrocytes in rheumatoid arthritis signalling, pulmonary fibrosis (WNT signalling) and the unfolded protein response, while the top upregulated pathways are the RAC, Integrin and Ephrin signalling pathways (figure 3D). Here, AKT1 is linked to rheumatoid arthritis.