CTLA4 and neoplasm: Moreover, 64Cu-DOTA-anti-CTLA-4 mAb showed higher tumor-to-blood and tumor-to-muscle ratios than 64Cu-DOTA-Control IgG (tumor-to-blood ratio: 0.58±0.03 vs. 0.40±0.02, p<0.001; tumor-to-muscle ratio: 8.48±0.63 and 5.31±0.35, p<0.01).