ID1 and prostate cancer: Like EGFR, upregulation of Id-1 is frequently found in many types of human cancer such as breast (Lin et al, 2000), pancreas (Maruyama et al, 1999), cervical (Schindl et al, 2001), head and neck (Langlands et al, 2000) and prostate cancer (Ouyang et al, 2002a), and increased Id-1 expression levels are associated with advanced tumour stage and poor prognosis (Maruyama et al, 1999; Schindl et al, 2001; Ouyang et al, 2002a).