MKP-1 knockout mice show higher ERK activation and display reduced adiposity and protection against obesityReduction of MKP-1 using antisense oligonucleotide results in higher ERK activation and leads to reduced adiposityMKP-3 deficient mice demonstrate resistance to diet-induced obesityJIP1 deficient mice demonstrate resistance to diet-induced obesity. The gene discussed is MAPK1; the disease is obesity due to melanocortin 4 receptor deficiency.