Recent studies have demonstrated that poly(ADP-ribosyl)ation (PARylation) of cellular proteins inhibits adipogenesis, and a whole-body knockout model of PARP1 was shown to develop obesity and increased adiposity [40,41,42], similar to the Ogg1−/− mouse [31]. This evidence concerns the gene OGG1 and obesity due to melanocortin 4 receptor deficiency.