In a murine MAFLD model, overnutrition contributes to hepatic steatosis by facilitating H3K4 methylation via H3K4 methyltransferase MLL4/KMT2D at steatotic target genes of PPARγ2 and activating their transcription (Table 1; Figure 2) (Kim et al., 2016). The gene discussed is KMT2D; the disease is fatty liver disease.