NRP1 and neoplasm: In particular, a specific population of monocytes co-expressing CD11b and the VEGF co-receptor Neuropilin-1 (NRP1), and named therefore neuropilin-expressing monocytes (NEM), do not stimulate endothelial proliferation and vascular growth, but specifically favor pericyte and smooth muscle cell recruitment during VEGF-induced angiogenesis by secreting transforming growth factor-β (TGF-β) and platelet-derived growth factor-BB (PDGF-BB) (Zacchigna et al, 2008), leading also to normalization of tumor vessels and inhibiting tumor growth (Carrer et al, 2012).