To better understand the role of IGFBP3/TMEM219 in controlling the beta-cell mass in vivo in disease conditions such as T1D, we pharmacologically modulated IGFBP3-mediated signaling with ecto-TMEM219 in a T1D prevention study in 10-week-old normoglycemic NOD mice. This evidence concerns the gene IGFBP3 and type 1 diabetes mellitus.