The procedures of total proteins extraction and Western blot were performed according to our previous description.17 (link) Simply, the cells were disrupted by RIPA lysis and the total proteins were collected by centrifugation. The denatured proteins (30 μg per lane) were separated by SDS-PAGE and subsequently transmitted into 0.22μm PVDF membrane. After blocked with 5% nonfat milk at room temperature for 1 hr, the membrane was incubated with rabbit anti-RKIP antibody (BBI, Shanghai, China) and mouse anti-GAPDH antibody (Abclonal, Wuhan, China), respectively, overnight at 4°C. Next, after incubated with anti-rabbit or anti-mouse IgG HRP-conjugated secondary antibodies, the protein amounts were visualized by chemiluminescent HRP substrate (EpiZyme, Shanghai, China). The equipment and the software of visualization are FluorChem FC3 (Protein Simple, CA, USA) and AlphaView SA (Protein Simple, CA, USA), respectively.