Medical Sciences. In the article “Differential suppression by protease inhibitors and cytokines of apoptosis induced by wild-type p53 and cytotoxic agents” by Joseph Lotem and Leo Sachs, which appeared in number 22, October 29, 1996, of Proc. Natl. Acad. Sci. USA (93, 12507–12512), due to a printer’s error the word “E64” was inserted by mistake in the second sentence of the Abstract after the word “(TPCK).” The correct second sentence should read: “Apoptosis was also suppressed by the serine and cysteine protease inhibitor N-tosyl-l-phenylalanine chloromethylketone (TPCK), but not by other serine or cysteine protease inhibitors including N^α-p-tosyl-l-lysine chloromethylketone (TLCK), E64, pepstatin A, or chymostatin.”