INS and type 2 diabetes mellitus: Functional experiments further showed that overexpression of PAX5, one of the genes upregulated in T2D, led to reduced insulin secretion, suppression of mitochondrial respiration, and disruption of energy balance through regulation of downstream genes such as BARX1, NEFL, PCOLCE2, and SFRP1 (Bacos et al., 2023).