To further give a new insight and investigate the role of Mir342 in obesity and diabetes, we obtained Sanger MirKO ES cell line Mir342 (Mir342tm1Wtsi) from MMRRC (Mutant Mouse Resource & Research Centers) and generated Mir342 knockout mice [Mir342 (-/-)]. The gene discussed is MIR342; the disease is obesity due to melanocortin 4 receptor deficiency.