FN1 and neoplasm: To determine whether tumor cell adherence to Col1 is regulated during EMT, we initially quantified cell attachment to collagen- or fibronectin-coated wells using a panel of KP cell lines classified previously as mesenchymal or epithelial (Supplemental Table 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.153948DS1) (20).