PTPN2 and diabetes mellitus: • Diabetes-related GLIS deficiency leads to preferential upregulation of the BimS isoform.• Diabetes-related PTPN2 deficiency leads to STAT-1-mediated Bim upregulation.• Deficiency of BACH2 leads to downregulation of PTPN2 and Bim upregulation.• Reduced expression of Cathepsin H leads to increased Bim expression.