The role of angiogenesis in thymic tumorigenesis was noted in a study by Tomita et al., who evaluated 46 surgically resected TETs via IHC and reported that the mean micro-vessel density correlated with tumor invasiveness, noting a higher expression of vascular endothelial growth factor (VEGF) in more aggressive TET histologies, such as invasive thymoma and thymic carcinoma, compared with non-invasive thymoma [80]. This evidence concerns the gene VEGFA and thymic epithelial neoplasm.