NRP1flflNRP2flfl.ECKO PyMT-BO1 tumors were found to be approximately 70% less vascularized than respective Cre-negative control tumors (Fig. 3M and N; Supplementary Fig. S2A and S2B), corroborating our CMT19T studies, and confirming that the expression of NRP1 and NRP2 is essential for tumor angiogenesis in multiple cancer models. The gene discussed is NRP1; the disease is cancer.