DGAT2 and steatosis: Across multiple independent experiments, and using both APOB−/− and MTTP−/− organoids as FatTracer models, we found 100% fidelity in genotype–phenotype correlation—that is, fat-resolved organoids always carried homozygous DGAT2 mutations while steatosis-presenting organoids carried no or heterozygous DGAT2 mutations (Fig. 5g).