“…In addition Iggo et al (1990) Iggo et al, 1990;Harlow et al, 1985;Bartek et al, 1990;Takahashi et al, 1989 andChiba et al (1990). Chiba et al (1990) We have previously demonstrated that there is elevated expression of several oncogenes, (Ha-ras, Ki-ras, c-erbB-2 and c-myc) in the development of squamous cell carcinoma of the head and neck (Field et al, 1986(Field et al, , 1987(Field et al, , 1989(Field et al, , 1990Field, 1991). We have reported a correlation between elevated c-myc oncoprotein expression and poor prognosis (Field et al, 1989), but as yet there is no published evidence to demonstrate that amplification or point mutations of oncogenes are associated with the clinical outcome of these patients (Saranath, 1989;Rumsby et al, 1989;Sheng et al, 1990;Field et al, unpublished).…”