Crosstalk between VEGF and novel angiogenic protein regulates tumor angiogenesis and contributes to aggressiveness of breast carcinoma

► NAP isolated from SF is found in tumor cells and human breast cancer biopsies. ► NAP is a permeability factor inducing angiogenesis in cell-based and in vivo assays. ► Functional mAb against NAP abrogated proangiogenic properties of NAP. ► NAP is a substrate for p38 MAPK for VEGF signaling in tumor cells. ► Angiogenic signaling by NAP involves JNK besides upregulation of VEGF and VEGFR genes.