Western blot analysis

Protein samples were lysed using RIPA buffer (Beyotime, Shanghai, China). Then, we collected the supernatant as the total proteins. The proteins were electrophoresed by 10% SDS‐PAGE and then blocked with 5% nonfat milk for one hour. After incubating the protein with the following primary antibodies (FRS2 and GAPDH) overnight at 4°C, the diluted secondary antibodies was added to incubate protein for another one hour. Finally, the protein was examined using ECL reagent (Millipore, MA, USA).