More importantly, our genetic lineage tracing study indicated that virtually no DPP4+ cells became adipocytes in iWAT during beige adipogenesis, whereas HFD feeding induced the differentiation of DPP4+ cells to adipocytes, which may suggest the pathologic role of DPP4+ cell lineages in the hyperplastic expansion of WAT during obesity. This evidence concerns the gene DPP4 and obesity due to melanocortin 4 receptor deficiency.