FKBP5 and leiomyoma: To assess transfection efficiency, FKBP5 mRNA levels were measured and found to be reduced by 13-fold in FKBP5 siRNA-transfected leiomyoma cell cultures compared to those transfected with scramble siRNA (.08 ± 0.04 vs 1.04 ± 0.14; P < .001).