“…Moreover, metabolomic studies indicate that H 2 S can stimulate the activity of multiple Krebs cycle enzymes [ 56 , 58 ]. H 2 S was also found to upregulate glucose uptake in various cell types [ 171 , 172 , 173 , 174 ]; this may be very important to support the high glucose utilization of the cancer cell. Multiple metabolomic studies and genome wide gene expression studies [ 56 , 58 , 174 ] suggest that endogenously produced H 2 S plays a role in the reprogramming of the pyrimidine and purine metabolism, amino acid metabolism, nicotinate and nicotinamide metabolism, fatty acid metabolism, glutamate metabolism, the urea cycle, and several other pathways.…”