MSCs expressing Ptpn11+/+ or Ptpn11E76K/+ were lysed for proteomic analysis. In brief, 0.5 μg of peptide mixture resolved in buffer A (0.1% formic acid) was loaded onto a 2‒cm self‒packed trap column using buffer A and separated on a 150 μm‒inner‒diameter column with a length of 15 cm over a 78‒min gradient at a flow rate of 600 nl/min. An Orbitrap Fusion mass spectrometer (Thermo Fisher) was operated in positive‒ion mode at an ion transfer tube temperature of 320°C. The positive‒ion spray voltage was 2.0 kV. The Orbitrap Fusion Lumos was set to the OT–IT mode. For a full mass spectrometry survey scan, the target value was 5×105, and the scan ranged from 300 to 1400 m/z at a resolution of 120000 and a maximum injection time of 50 ms. For the MS2 scan, a duty cycle of 3 s was set with the top‒speed mode. Only spectra with a charge state of 2–6 were selected for fragmentation by higher‒energy collision dissociation with a normalized collision energy of 35%. The MS2 spectra were acquired in the ion trap in rapid mode with an AGC target of 7,000 and a maximum injection time of 35 ms, and the dynamic exclusion was set to 18 s.