Using eQTLs obtained from both normal breast tissue and blood, increased expression of ras homolog family member D (RHOD) was positively associated with overall and ER+ breast cancer risk (Overall breast cancer: Odds ratio (OR) per standard deviation (SD) increase in expression level 1.06; (95% confidence interval (CI) 1.03, 1.09; P = 5.65 × 10–5) and OR 1.22 (95% CI 1.11, 1.35; P = 5.22 × 10–5) in normal breast tissue and blood respectively. The gene discussed is RHOD; the disease is breast cancer.