CX3CL1 and obesity due to melanocortin 4 receptor deficiency: Myokines such as CXCL10, CX3CL1 (fractalkine), and follistatin influence the interaction between skeletal muscle and pancreatic β-cells.181 Evidence suggests that CXCL10 may have harmful effects by impairing insulin secretion and promoting β-cell apoptosis.181 In contrast, CX3CL1 appears to exert beneficial actions; chronic administration of a fractalkine analog in various rodent models of obesity has been shown to improve glucose tolerance and reduce β-cell apoptosis,182 underscoring its positive role in maintaining glucose homeostasis.