Retraction

Applied Biological Sciences. In the articles “4,5-Dianilinophthalimide: A protein-tyrosine kinase inhibitor with selectivity for the epidermal growth factor receptor signal transduction pathway and potent in vivo antitumor activity” by Elisabeth Buchdunger, Uwe Trinks, Helmut Mett, Urs Regenass, Marcel Müller, Thomas Meyer, Elaine McGlynn, Lorenzo A. Pinna, Peter Traxler, and Nicholas B. Lydon, which appeared in number 6, March 15, 1994, of Proc. Natl. Acad. Sci. USA (91, 2334–2338) and “Selective inhibition of the platelet-derived growth factor signal transduction pathway by a protein-tyrosine kinase inhibitor of the 2-phenylaminopyrimidine class” by Elisabeth Buchdunger, Jürg Zimmermann, Helmut Mett, Thomas Meyer, Marcel Müller, Urs Regenass, and Nicholas B. Lydon, which appeared in number 7, March 28, 1995, of Proc. Natl. Acad. Sci. USA (92, 2558–2562), the undersigned authors wish to note the following. “In the interest of scientific accuracy and our mutual desire with the editors that only high quality and reliable data are published, we regret to say that the in vivo data for the articles above are not considered reliable. We wish to retract the data until the in vivo experiments have been repeated and reevaluated. The validity of in vitro and cellular data is not in doubt. We very much regret this situation.”