TNC and cancer: Besides, the reaction site where human TNC binds to α9β1 is located in the isoleucine-aspartic acid-glycine motif within the third fibronectin type III repeat, which is absent in mice, which may explain why cancer rarely metastasizes to the bone in murine models, while both integrin-α9β1 and TNC are thought to have great significance in metastatic prostate cancer (81, 82).