A similar decoupling of obesity and metabolic disturbances has been noted in other studies when suppressing adaptive immunity, for example in RAG-1-deficient mice, which lack mature T and B lymphocytes.8 Given observations that LDL production is increased by obesity19 and that HSP60 autoimmunity contributes to atherosclerosis,12 the reduction in LDL levels achieved by HSP60 peptide treatment is of interest. The gene discussed is RAG1; the disease is obesity due to melanocortin 4 receptor deficiency.