BMP2 and osteoarthritis: investigated cartilage regeneration mechanisms in osteoarthritis using hyaluronic acid and platelet‐rich plasma, finding that they activate TGF‐βRII and downstream Smad2/3 signaling.[43] Therefore, it is hypothesized that the study mediated by porous HAMA hydrogels could stimulate fibrocartilage regeneration by BMP‐2 mainly through the TGF‐β/Smad2/3 pathway.