FN1 and breast cancer: In pancreatic cancer, the integrin β1 subunit mediates the tumor cell interaction with the tumor microenvironment and ECM proteins, such as types I and IV collagen, laminin, and fibronectin (56); in breast cancer, colorectal cancer, and lung and hepatocellular carcinoma, integrin has been linked to tumor evolution and aggressiveness (24, 25, 28, 57).