However, RNAs for four genes were significantly elevated in MP compared to NP mice including several neurotrophic factors: Deleted in colorectal cancer Dcc (6.1×), Ephrin A4 Efna4 (3.4×), and nerve growth factor Ngf (56×); by contrast, netrin 3 Ntn3 was significantly reduced in expression (0.11×) in MP corneal epithelium compared to NP. Here, NGF is linked to colorectal cancer.