IDH1 and obesity due to melanocortin 4 receptor deficiency: Risk factors for VTE in this subtype can be classified into patient related (i.e., older age, obesity, lower limb paresis, and history of VTE); tumor disease type, including glioblastoma, IDH1, intratumor thrombus); and treatment related (namely biopsy, tumor resection, and use of corticosteroids/anti VEGF therapy).