BRCA1 and breast cancer: Additionally, in this case, no association was found between BRCA1 gene hypermethylation and tumor histology (OR = 0.81: 95% CI: 0.60–1.07; p = 0.14, fixed effects model, Figure 3a), tumor grading (OR = 0.80: 95% CI: 0.46–1.39; p = 0.43, fixed effects model, Figure 3c), and breast cancer molecular classification (OR = 1.93: 95% CI: 0.79–4.72; p = 0.15, random effects model, Figure 3e).