Persson and et al. additionally showed that patients older than 50 who used aromatase inhibitors and continued smoking had a significantly higher risk of events associated with breast cancer (HR 2.98), disease progressing to the metastatic stage (HR 4.19), and dying (HR 3.52), suggesting a possible interaction of smoking and commonly used aromatase inhibitors. The gene discussed is CYP19A1; the disease is breast cancer.