1Neil Q. McDonald and Gordon Peters are with the Imperial Cancer Research Fund, PO Box 123, 44 Lincoln's Inn Fields, London WC2A 3PX, U.K. N.Q.M. is also at the Department of Crystallography, Birbeck College, London WC1E 7HX
2email: peters@icrf.icnet.uk
Three-dimensional structures for the INK4 proteins should reveal how the plethora of p16INK4a mutations found in human tumors might alter its function as a cyclin-dependent kinase inhibitor.
