NRP1 and colorectal carcinoma: Notably, expression of endogenous NRP1-∆E4 and NRP1-∆E5 proteins and their intracellular accumulation could also be detected in the Pt93, Pt2377 and LM2377 primary CRC cell lines; of these Pt93 cells expressed both NRP1-∆E4 and NRP1-∆E5 proteins (Supplementary Fig. 2e, f).