Further, corresponding to the morphological changes of nucleolus in number and size, these highly proliferating SSEA1 cells demonstrated coexpression of either D2-40 or the mesodermal marker Scl (stem cell leukemia), brachyury, and Flk-1 (vascular endothelial growth factor-2), respectively, indicative of the neoplasmtic transformation into the stromal or vascular cells.
Consistent with an embryologically derived hemangioblast, the neoplastic cells demonstrated coexpression of the mesodermal markers brachyury, Flk-1 (vascular endothelial growth factor-2), and stem cell leukemia (Scl).