Within DCIS, two different vascular patterns have been observed: a “necklace” of vessels surrounding the DCIS-affected duct and a “diffuse stromal” pattern, where an increase in microvessels is seen in the surrounding stroma (160–162) with the necklace pattern associated with different levels of the angiogenic factor thymidine phosphorylase arising from the DCIS tumor cells (163). The gene discussed is TYMP; the disease is ductal breast carcinoma in situ.