Neurobiology. In the article “Caspase-1 is activated in neural cells and tissue with amyotrophic lateral sclerosis-associated mutations in copper-zinc superoxide dismutase” by Piera Pasinelli, David R. Borchelt, Megan K. Houseweart, Don W. Cleveland, and Robert H. Brown, Jr., which appeared in number 26, December 22, 1998, of Proc. Natl. Acad. Sci. USA (95, 15763–15768), the following corrections should be noted. An erroneous version of Fig. 6 was published. The lane indicated as G41D represents lumbo-sacral spinal cord extract from G85R transgenic mice. In Fig. 7a, cell viability is expressed as % of untreated cells and not as % of viability.