INS and diabetes mellitus: However, the hallmark of this disease is insufficient insulin secretion due to β-cell loss resulting from autoimmune attack, as in type 1 diabetes (T1D), or an impairment of the β-cell function or insulin resistance built up by peripheral tissues, as in type 2 diabetes (T2D) (American Diabetes and Association, 2013; Johannesson et al., 2015).