In the MR analysis of our five CRP-SNPs, a 1-unit increase in the genetically predicted chronic inflammation (defined as >3.0 mg/L of CRP) was associated with approximately 80% decreased risk of breast cancer among E + P users, particularly in women with <5-years’ use of E + P (PWM-HR1st-stage = 0.17, 95% CI: 0.05–0.63) (Table 1). This evidence concerns the gene CRP and breast cancer.