Fig. 2.

Clonogenic survival curves. Canine OSA cells were treated with radiation only (“control”) or in combination with erlotinib at 10 μM (“erlotinib”) given 4-6 h before radiation. Experiments were repeated three times and average of results are shown. Survival fractions are plotted on a log-scale. Erlotinib treatment resulted in statistically significant reduction in cell survival of Dharma cells for radiation doses of 0, 2, 4 and 6 Gy, and statistically significant reduction in cell survival for D17 cells at 0 Gy, but did not promote enhancement of radiation effects for D17 or Abrams cell lines. *p < 0.05 indicates statistical significant reduction in clonogenic survival compared to control at the corresponding radiation dose