INS and type 1 diabetes mellitus: in which reductions in DNMT1 and ARX expression in alpha-cells from islets of T1DM donors were associated with increased expression of beta-cell markers, PDX1 and NKX6. 1 (67), and furthermore, this group found that the selective loss of alpha-cell Arx and Dnmt1 expression led to an increase in alpha-cell-derived bihormonal insulin+/glucagon+ cells in mouse islets (67).