NRP1 and liver cancer: Nevertheless, a significant correlation was observed between high expression of NRP1 and the presence of vascular invasion (invasion, OR 2.48, 95% CI 1.63–3.76, p < 0.001) in liver cancer studies and metastasis (OR 2.19, 95% CI 1.46–3.26, p < 0.001) in both tumor types (Figure 4b).