CYP11B2 and urokinase-type plasminogen activator measurement: Previous studies reported high expression of CXCR4 in 71% to 96% of patients with APA.16,17 van de Wiel et al44 performed immunohistochemistry analysis on adrenal nodules from patients with UPA and reported that every CYP11B2-positive nodule showed CXCR4 staining.