RB1 and osteosarcoma: In addition, Ub-like with PHD and RING finger domain 1 (UHRF1), a member of a subfamily of RING-finger type Ub E3 ligases, is highly expressed in many human cancers, which suppresses the expression of E-cadherin through targeting retinoblastoma 1 (Rb1), thus promoting epithelial-to-mesenchymal transition (EMT) in human osteosarcoma cells (Unoki et al., 2010; Liu et al., 2016).