FADS1 and metabolic dysfunction-associated steatohepatitis: For instance, recently we and others, using different approaches, have shown that FADS1 (i.e., Δ5-desaturase) polymorphism can decrease enzyme activity leading to the accumulation of toxic fatty acids upstream in the pathway and decrease the downstream phosphatidylcholine to phosphatidylethanolamine ratio in NASH patients, leading to hepatocyte death and release of lipids that are toxic for the surrounding hepatocytes [19,20,35].