EGFR and cancer: Recent studies have suggested that gefitinib induces cell cycle retardation and apoptosis, and inhibits the growth of several types of human cancer cells expressing EGFR both in vitro and in vivo (Ciardiello et al, 2000; Sirotnak et al, 2000; Ciardiello et al, 2001; Moasser et al, 2001; Moulder et al, 2001; Bianco et al, 2002; Ciardiello et al, 2002; Fujimura et al, 2002; Huang et al, 2002; Janne et al, 2002; Magne et al, 2002; Williams et al, 2002).