Erratum
1 Laboratory of Molecular Cardiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
2 Laboratory of Molecular Otology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892
In the report "Polarity and velocity of sliding filaments: Control of direction by actin and of speed by myosin" by J. R. Sellers and B. Kachar (27 July, p. 406), figure 4 (p. 407) was incorrectly printed. The correct figure appears below.