4-(4-(4-(3-fluorobenzyloxy)-3-chlorophenylamino)quinazolin-6-yl)phenol, is a derivative of the quinazoline containing drug L. L reversibly blocks phosphorylation of the epidermal growth factor receptor (EGFR), ErbB2, and the Erk-1 and-2 and AKT kinases; it also inhibits cyclin D protein levels in human tumor cell lines and xenografts.