MIEF1 and obesity due to melanocortin 4 receptor deficiency: Meanwhile, Mief1 (mitochondrial elongation factor 1), which lies in the dominant Fob2 (Fat line obesity QTL 2) confidence interval identified in our previous study (Horvat et al. 2000), and Mrpl3 (mitochondrial ribosomal protein L3) encode proteins involved in mitochondrial translation and biogenesis.