Zhao et al. found that USP9X is a key deubiquitylating enzyme for the stabilization and high activity of NRP-1, and that USP9X binds to and stabilizes the expression of NRP-1, and that up-regulated NRP-1 can activate hepatic stellate cells to promote the progression of liver fibrosis 83. Here, NRP1 is linked to Hepatic fibrosis.