PTPRC and type 1 diabetes mellitus: To address whether the downregulation of Cdk11 mRNA prior to T1D onset altered the NOD beta cell replicative activity, we assessed the beta cell proliferation rates using Ki67 staining of GLUT-2+ CD45- (beta) cells from 11-week-old NOD and NOD/SCID mice and analyzed these rates by flow cytometry (Figure 1E).