When all study populations combined, dismal survival outcomes on BC patients with hypermethylation of RASSF1A promoter were observed: for overall survival, summary HR = 3.47, 95%CI 1.44–8.34; I2 = 72.70%, random-effects model (Figure 1), and for disease free survival, summary HR = 2.75, 95% CI 1.96–3.84; I2 = 0.00%, fixed-effects model (Figure 2). The gene discussed is RASSF1; the disease is breast cancer.