Effects of C225 and/or radiotherapy on the hypoxic fraction (HF) and BrdUrd labeling index (LI) of 4 SCCNij lines: A) SCCNij202, B) SCCNij167, C) SCCNij153, D) SCCNij185. Tumors were treated with C225 (1 mg i.p.) and/or 10 Gy radiotherapy and harvested 1 or 4 days after radiotherapy and/or 1, 2 or 5 days after C225. Tumors harvested 2 or 5 days after C225 correspond with tumors harvested 1 or 4 days after combined C225-radiotherapy, respectively. Differences between treated tumors and controls were tested for significance using Mann-Whitney tests, *: p<0.05, **: p<0.01. Error bars represent SEM. Number of animals per group varied from 4 to 6.