NRP1 and monocytic leukemia: Human THP1 monocytic leukemia cells that were treated with phorbol 12-myristate 13-acetate (PMA) also expressed NRP-1 (Figure 1D), shown via the use of an anti-hNRP-1 mAb, and also bound Nb1, Nb2, Nb3, Nb4, Nb6, Nb7 and Nb8 (Figure 1E).