To investigate whether HectH9-mediated HIF-1α stabilization indeed occurs in human cancers and to evaluate the prognostic significance of HIF-1α/HectH9 co-expression, tissue-microarray immunohistochemistry (IHC) analysis of HIF-1α and HectH9 expression was performed in 190 sets of resected stage I lung adenocarcinoma patient samples (Supplementary Table 1, IHC staining from a representative case was shown in Fig. 8f). This evidence concerns the gene HUWE1 and lung adenocarcinoma.