SLC7A5 and type 2 diabetes mellitus: To investigate whether the higher SLC7A5 methylation rate translated to changes in gene expression following histidine supplementation, we performed QPCR analysis and found that in the T2D group the expression of SLC7A5 was significantly increased upon histidine intake, while it remained unchanged in the control group in line with the unchanged SLC7A5 methylation in healthy controls (Figure 6(c)).