MTTP and steatosis: Many molecules have been found to be involved in lipid metabolism, such as GCKR for de novo lipogenesis; apoB, TM6SF2 and MTTP for VLDL assembly and secretion; PNPLA3(I148M) accumulation on lipid droplets; and the nuclear envelope-localized torsinA-LAP1 complex for hepatic VLDL secretion and steatosis [29–33].