SEMA3A and Hypoglycemia: Soluble isoforms of NRP1 (sNRP1) also exist without transmembrane or cytoplasmic domains, expressing only the extracellular domains which allow them to bind NRP1 ligands (21); therefore, the plasma levels of NRP1 ligands (VEGFA and SEMA3A) were determined in response to insulin-induced hypoglycemia.