IGF1 and obesity due to melanocortin 4 receptor deficiency: In addition, the obesity-related metabolic perturbations, including dysregulation of insulin, IGF1, adipokines, inflammatory factors (e.g., cytokines), and vascular integrity-related factors (e.g., vascular endothelial growth factor) [4] promote a tumor microenvironment associated with a reduced efficacy of anticancer treatments [5,6].