VHL and renal cell adenocarcinoma: Similarly, suppression of HIF-1α, but not HIF-2α by siRNA reduced BHLHE41 expression in in VHL-defective RCC L13 or VHL re-expressing RCC4 and VHL wild-type HK2 cells which were stimulated with a HIF prolyl hydroxylase inhibitor, dimethyloxalylglycine (DMOG)(Fig 2D and 2E, S1 Fig).