Interestingly, incubation with palmitate led to the upregulation of LPA4, LPA5 and LPA6 in HL-1 cells (Fig 2C), similar to obesity-induced increases in the expression of these receptors in primary mouse cardiomyocytes and/or ventricles (Fig 2A). The gene discussed is LPAR4; the disease is obesity due to melanocortin 4 receptor deficiency.