CYP7B1 and metabolic dysfunction-associated steatohepatitis: However, here we show that loss of the enzymes CH25H and CYP7B1, and thus inhibition of 25-HC and 7α,25-diHC synthesis, did not show any significant differences in NASH activity compared with their wild-type littermate controls, arguing against an essential role of these two enzymes and their immediate products in NASH pathogenesis.