SIRT6 and breast cancer: Notably, further subgroup analysis revealed that overexpression of SIRT1 and SIRT6 predicted poor OS (HR = 2.65, 95% CI 1.54–4.56; HR = 2.53, 95% CI 1.64–3.90, respectively) and DFS (HR = 1.65, 95% CI 1.07–2.56; HR = 2.74; 95% CI 1.88–4.01, respectively) in BC.