Furthermore, disrupted CD44 expression (fragment) is enhanced in osteoarthritis (OA) patients.[48] We found that M2 macrophages at the injury site express Lgals9, which could activate Cd44 on nearby cycling MSCs, and macrophages reportedly promote HO formation, suggesting Cd44 participates in both chondrogenic and osteogenic differentiation. This evidence concerns the gene LGALS9 and osteoarthritis.