CYP19A1 and breast cancer: Kurland et al. [28] have studied changes in FDG uptake in breast cancer patients undergoing treatment with aromatase inhibitors and found that the degree of flare was less at 2 weeks (no patient had an increase in FDG SUV >11%) and for 11 patients who had a decrease in FDG uptake >20%, there was a correlation with the post-treatment Ki-67 (i.e., all of these patients had a Ki-67 post-treatment value of ≤5%.