SLC7A5 and diabetes mellitus: SLC7A5 plays an important role in cell growth and development by absorption of eight out of nine essential amino acids.49 In fact histidine is the preferred substrate of SLC7A549 and expression of SLC7A5 gene expression is regulated by DNA methylation in the promotor region.50 In addition, hyperglycemia reduces SLC7A5 expression,59,60 which may contribute to sarcopenia in diabetes.