With the help of effects from the possible intermediate JAG1 in the conditioned medium, linc-OIP5 could regulate YAP1/JAG1 signaling in breast cancer cells to further control DLL4/Notch/NRP1 signaling in co-cultured HUVECs, which maybe a novel mechanism of angiogenic regulations with abrogating direct apposition in a breast cancer microenvironment. Here, DLL4 is linked to breast cancer.