Correspondingly, mice with the deletion of ERK genes are resistant to HFD-induced obesity, which was consistent with the suppressed expression of C/EBP-α and PPAR-γ in 3T3-L1 preadipocytes upon blockage of MEK/ERK cascades [15,49]. The gene discussed is PPARG; the disease is obesity due to melanocortin 4 receptor deficiency.