For example, forced netrin-1 overexpression in the mouse intestine results in hyperplasia and adenoma formation14, autocrine netrin-1 expression is implicated in the progression of experimental inflammatory bowel disease to colorectal cancer15, autocrine netrin-1 expression promotes experimental breast cancer metastasis16, and in glioma, netrin-1 promotes cancer cell invasion and stemness17. This evidence concerns the gene NTN1 and breast cancer.