CTLA4 and breast cancer: Yu et al. showed that CTLA-4+ lymphocyte density high was an independent predictor of better DFS (HR = 0.315, 95% CI: 0.15–0.658, p = 0.002) and OS (HR = 0.313, 95% CI: 0.139–0.703, p = 0.005), whereas tumor CTLA-4high was an independent predictor of shorter DFS (HR = 2.176, 95% CI: 1.084–4.437, p = 0.029) and OS (HR = 2.820, 95% CI: 1.337–5.95, p = 0.007) in 130 patients with operable breast cancer [33].