Tumour hypoxia, as measured by high expression of HIF-1α (r = 0.42, p = 0.07) and CA-9 (r = 0.46, p = 0.03), was positively correlated with tumour grade (atypical hyperplasia, n = 2, grade 1, n = 15, grade 2, n = 1 and grade 3, n = 4) (Fig. 1a, b) and both hypoxia markers positively correlated with each other (r = 0.45, p = 0.004). Here, HIF1A is linked to neoplasm.