It is known that G6PD knockdown impairs NADPH production and causes ROS accumulation, which then promotes the activation of JNK and tumour regression through DNA damage repair.24 Herein, the metabolites belong to PPP were firstly analysed by mass spectrum to confirm that G6PD knockdown decreased the level of NADPH in both OSCC cell lines (Supplementary Fig. 3A, B), accompany with the increase of ROS levels (Supplementary Fig. 3C). This evidence concerns the gene MAPK8 and neoplasm.