To confirm our hypothesis that NRP2 induces a constitutive activation of the TGFβ1 pathway, we used a TGF-β1 signaling reporter assay for the quantification of TGF-β1-induced smad2/3 signaling in HT29ctrl, HT29NRP2, Colo320siRNA-ctrl and Colo320siRNA-NRP2 colorectal cancer cells. Here, TGFB1 is linked to colorectal cancer.