title: Correction.
abstract: The following sentence was omitted from the acknowledgment section of our report "Independent human MAP kinase signal transduction pathways defined by MEK and MKK isoforms" (3 Feb., p. 682)(1) because of an error. "A. Lin and M. Karin are acknowledged for informing us abut the presence of an upstream in-frame initiation codon in the sequence of human MKK4/JNKK/SEK1 before publication."
authors.forename: R J
authors.initials: RJ
authors.lastname: Davis