CD80 and neoplasm: When monitoring tumor growth over time with a caliper, we observed no significant difference in tumor volumes between the untreated control group (G1) and the rats receiving low dose cyclophosphamide (CY, 30 μg/dose) in week two (G4), B7.1-Fc fusion protein only (G3), B7.1-Fc protein plus CY (G2) or vaccine plus CY only (G5) (Figure 2A).