ARG1 and obesity due to melanocortin 4 receptor deficiency: Importantly, we noticed that CNNM4 expression was positively correlated with M2 macrophage marker genes such as CD301, MRC1, ARG1, and IL10, while negatively correlated with M1 macrophage marker genes such as RANTES, MCP1, and TNFα, indicating that decreased CNNM4 expression levels and Mg secretion might contribute to the progress of obesity.