Mice were i.v. injected with anti-CTLA-4 antibody at different days (20 μg per mouse each time) for two rounds of treatment, with the first round given right after their first tumours were eliminated (days 1 and 5), and the second round given right after their secondary tumours were re-inoculated (days 41, 44 and 47) (Fig. 5a). This evidence concerns the gene CTLA4 and neoplasm.