NGFR and colorectal carcinoma: The tumor sizes of NGFR transfectants were significantly smaller than those of vector transfectants after an intraperitoneal injection of 5-FU (vector vs. NGFR: 500.9 ± 198.0 mm3 vs. 82.6 ± 36.8 mm3, P < 0.001) (Figures 4E, F), confirming that NGFR acts as a chemotherapeutic enhancer in CRC.