TM6SF2 and metabolic dysfunction-associated steatohepatitis: The estimated heritability is at least 50%; genome-wide association studies have implicated a number of genetic variants involved in lipid metabolism, including in PNPLA3 and TM6SF2. 9In 10–20% of individuals, hepatic steatosis can be complicated by a state of inflammation, lipotoxicity and apoptosis known as metabolic dysfunction-associated steatohepatitis (MASH).