Thus, we expected that tumour cells would have a higher rate of proliferation, more frequently undergo cell division, and be more sensitive to radiation in patients with a higher Ki-67 proliferation index before treatment; when we compared the mean Ki-67 proliferation index of the two groups (≥79.77% vs. <79.77%), tumour responses in terms of the CR rate were greater in the group with a Ki-67 proliferation index equal to or higher than the mean, as we expected. The gene discussed is MKI67; the disease is neoplasm.