Berra et al (2003) showed that under normoxic conditions, siRNA inhibition of PHD2, but not PHD1 or PHD3 resulted in the stabilisation of HIF-1α. Interestingly, the same author found PHD2 was upregulated by hypoxia, suggesting changes in PHD2 levels were not responsible for HIF-1α stabilisation under low oxygen tensions. This is supported by our study of BRCA1 tumours, where upregulation of HIF-1α was not associated with changes in PHD2 expression. Here, BRCA1 is linked to neoplasm.