FGF1 and malignant colon neoplasm: When the population of DLD-1 colon cancer cells that stably express WT FGF1 or R50E were injected subcutaneously into nude mice (1 million cells/site, two sites per mouse), cells that secrete WT FGF1 generated bigger tumors (n = 8) but cells that secrete R50E generated smaller tumors (n = 8) than mock-transfected cells (n = 7) (Fig. 1d and 1e).