BRCA1 and bile duct cancer: The evidence, shown in this paper, that BRCA1-KO fibroblasts turn into gallbladder, colon and bile duct cancer after exposure to sera of patients with only dysplastic lesions is, in our opinion, the definitive proof that the metastatic process might be independent from cell migration and entirely reproducible at distance by malignant transformation mediated through onco-factors circulating in the serum.