TGFβ signalling (Extended Data Fig. 5) is intricately involved in the pathogenesis of osteoarthritis through its effects on chondrocyte and osteoblast differentiation, skeletal development, cartilage and bone formation, inflammation, ECM remodelling, osteophyte and synovial tissue changes, and interactions with other signalling pathways, such as BMP. Here, TGFB1 is linked to osteoarthritis.