Figure 4. Summary of the difference in the role of gene transcription in PNPLA3148M pathogenesis between human and mouse. Transcriptional variability of 148I isoform does not lead to hepatosteatosis. Very low expression of 148M isoform in mice due to the low baseline Pnpla3 expression does not induce steatosis as well. However, increased expression of PNPLA3148M in mice or a higher baseline transcriptional level of PNPLA3148M in humans leads to steatosis. This highlights the “dominant-negative” effect of the 148M allele in both species. Tg = transgenic, KO = knockout, KI = knockin.