HIF1A and neoplasm: Patients with a HIF-1α positive primary tumour had an increased incidence of IBTR as a first event within 5 years compared to patients with a HIF-1α negative primary tumour both in the total patient population (HR0–5 yrs = 1.9 [1.3–2.9], p = 0.003, Fig. 2a and Table 2) and among patients that did not receive RT (HR0-5 yrs = 1.7 [1.1–2.8], p = 0.02, Fig. 2b and Table 2).