INSIG1 and steatosis: Acute knockout of the lipid biosynthesis inhibitor Insig1, the growth inhibitor Pten 95, the integrated stress response inhibitor Eif2α (Eif2s1), and the alanine-tRNA synthetase Aars all caused steatosis, as measured by enlargement and increase in signal from lipid droplets, marked by anti-Perilipin (Figures 7G and 7H).