IFNA1 and colorectal cancer: Fifty-six patients with untreated, advanced, measurable colorectal cancer were treated with two biweekly cycles of FUra bolus (600 mg m(-2)), modulated by MTX (24 h earlier, 200 mg m(-2)), and n-beta-IFN (3 x 10(6) IU i.m. every 12 h, starting at the time of FUra administration for four doses), alternating with a 3-week continuous infusion of FUra (200 mg m(-2) daily), modulated by 6-s-LV (20 mg m(-2) weekly bolus).