AGRICULTURAL SCIENCES. For the article “Role of calpain in skeletal-muscle protein degradation” by Jing Huang and Neil E. Forsberg, which appeared in number 21, October 13, 1998, of Proc. Natl. Acad. Sci. USA (95, 12100–12105), the authors wish to correct the primer sequence used to generate the calpastatin inhibitory domain as follows: AGCCAGAAGCCAGGCGTCCCCAAGGGCTCC.