The contrasting role of ECs in regulating tumor dormancy was best demonstrated in the study by Ghajar et al. where stable microvascular networks helped maintained tumor dormancy but sprouting neovasculature and endothelial tip cells promoted metastatic growth via secretion of periostin (POSTN) and transforming growth factor-β (TGFβ-1). Here, TGFB1 is linked to neoplasm.