To shed light into this latter issue, earlier studies investigating primary tumours and paired metastases by IHC revealed different patterns of EGFR expression (McKay et al, 2002; Ooi et al, 2004; Scartozzi et al, 2004; Bralet et al, 2005; Italiano et al, 2005; Bibeau et al, 2006; Cappuzzo et al, 2007). Here, EGFR is linked to neoplasm.