In comparison, CA9 staining in Calu-6 tumours was evident in perinecrotic areas of the tumours (Fig. 3A) and hypoxic fractions in cediranib- and vehicle-treated animals were similar (14.8 ± 2.6% vs 12.1 ± 0.9%; P = 0.382; Fig. 3C), suggesting no significant effect of cediranib on Calu-6 tumour oxygenation. The gene discussed is CA9; the disease is neoplasm.