Over the last ten years, our own research group has studied the expression and the biological effects induced by an atypical fibronectin (FN) isoform, named oncofetal FN (onf-FN) [19,31,46,47,48], which was initially described by Hakomori’s group in the 1980s in both cancer cells and embryonic tissues [49]. The gene discussed is FN1; the disease is cancer.