SMURF2 and osteosarcoma: Huang et al. [67] discovered that the E3 ubiquitin ligase RLIM (RING finger LIM domain-binding protein) enhances the response of osteosarcoma U2OS cells to transforming growth factor-β (TGF-β) by directly interacting with the E3 ligase Smad ubiquitination-related factor 1 (Smurf2).