In the above article [Arima H, Yunomae K, Hirayama F and Uekama K (2001) J Pharmacol Exp Ther297:547–555], the authors regret that the forward and reverse primer sequences of human β-actin gene are incorrectly described (page 549). The correct forward and reverse primer sequences of human β-actin used in the study are 5′-TCCTGTGGCATCCACGAAACT-3′ and 5′-GAAGCATTTGCGGTGGACGAT-3′, respectively.

• The American Society for Pharmacology and Experimental Therapeutics