Medical Sciences. In the article “Production of β-defensins by human airway epithelia” by Pradeep K. Singh, Hong Peng Jia, Kerry Wiles, Jay Hesselberth, Lide Liu, Barbara-Ann D. Conway, Everett P. Greenberg, Erika V. Valore, Michael J. Welsh, Tomas Ganz, Brian F. Tack, and Paul B. McCray, Jr., which appeared in number 25, December 8, 1998, of Proc. Natl. Acad. Sci. USA (95, 14961–14966), due to a printer’s error, the following change should be noted: the symbol for Brian F. Tack should be ‡, to indicate that he is affiliated with the Department of Microbiology of the University of Iowa College of Medicine.