In nutshell, we identified seven hub genes (HIST2H2AA3, HIST2H2AA4, NFKBIA, SESN2, SMURF1, TGFβ1, TNRC6A) in T2DM vs. PC, six common hub genes (ATP6V0D1, ATP6V0C, ATP6V0E1, CTSD, CYBA, TGFβ1) in T2DM vs. LC and five common hub genes (ALYREF, CDKN2D, NGDN, THRAP3, UBE2M) in T2DM vs. BC, respectively (Fig. 3). The gene discussed is NGDN; the disease is breast cancer.