Notably, loss of endothelial Jag1 not only had an inhibitory effect in the neo-angiogenic and maturation responses but also had an angiocrine effect, through inhibition of Notch3/Hey in tumor cells, restricting proliferation, increasing apoptosis, and preventing the acquisition of an invasive phenotype by tumor cells, therefore inhibiting growth and development of subcutaneous LLC tumor transplants and autochthonous prostatic tumors in mice. Here, JAG1 is linked to neoplasm.