Considering that PPARα is a pivotal transcription factor functioning as a lipid sensor in the liver and thus regulating the expression of numerous genes involved in metabolic processes, including peroxisomal and mitochondrial β-oxidation, epigenetic variations within PPARα lead to a downregulation of β-oxidation activity, promoting the development of pathological conditions such as hyperlipidemia, obesity, and T2D [240,241]. This evidence concerns the gene PPARA and obesity due to melanocortin 4 receptor deficiency.