GBP1 and colorectal cancer: Finally, a colorectal cancer cell line (DLD‐1) stably transfected with the Ost‐F‐GBP‐1 expression plasmid was able to express and secrete high amounts of the full‐length protein but not p47‐GBP‐1 (Fig. 4D), indicating an interdependence between protein cleavage and secretion pathway.