highly significantp < 0-0001
The relative radiosensitivity of the tumour in the OH compared to FFC nlice, virtually a measure of the effect of the changed genetic 5700 = 1-4 milieu, can be expressed as the ratio of the two LDzio S, 3950 4 (+ 0-05*). The magnitude of this ratio compared to its standard error shows the difference in radiosensitivity of the two groups to be highly significant (p < 0-0001).