GDF3 and obesity due to melanocortin 4 receptor deficiency: Similarly, in adipose tissue metabolism, AKL7 can participate in the differentiation of adipocytes by mediating the growth differentiation factor 3 (GDF3) signaling pathway, causing the accumulation of adipose tissue in the body, aggravating insulin resistance, and leading to the occurrence of obesity; hyperglycemia can also upregulate ALK7 expression, which in turn acts on the pancreas to reduce insulin release and insulin resistance, resulting in a vicious circle of continuous rise in blood sugar.