This downregulation may be, at least in part, due to ablation of the transcriptional regulation of CSE and CBS expression by thyroid hormone signaling [45, 46], although multiple other processes may also be involved; for instance, the increased reactive oxygen species “burden” that occurs during aging may lead to an increased oxidative “consumption” of H2S [7]; a similar phenomenon has been also demonstrated in the context of diabetes-associated vascular dysfunction [47]. The gene discussed is CBS; the disease is diabetes mellitus.