NRP2 and neoplasm: While 1.106 Colo320siRNA-ctrl cells injected subcutaneously into nude mice induced tumor engraftment in all mice, NRP2 inhibition using specific siRNA prevented Colo320 engraftment in all animals suggesting a critical role of NRP2 in the early events contributing to tumor formation (Figure 3B).The influence of NRP2 inhibition using specific siRNA on Colo320 tumorigenicity was confirmed in vitro.