In addition, in pancreatic islets of T2D donors, Cinti et al. observed that dedifferentiated β cells (defined as insulin-/other hormones-negative and ChgA+/Syp+) showed the reduction and mislocalization of FOXO1 and NKX6.1 TFs and were enriched in ALDH1A3 (Aldehyde Dehydrogenase 1a3), previously demonstrated to be a marker of β cell dedifferentiation in T2D animal models [24,25,26]. The gene discussed is FOXO1; the disease is type 2 diabetes mellitus.