EGFR and neoplasm: The biomarkers include circulating markers in the blood, such as Epstein–Barr virus (EBV) DNA (Chien et al, 2001) and CYFRA 21-1 (Ma et al, 2004), as well as tumour immunohistochemical markers such as the expression of multidrug-resistance protein (Hsu et al, 2002), epidermal growth factor receptors (Chua et al, 2004) and signal transducers and activators of transcription factors (Hsiao et al, 2003).