HnRNPA1 binds repressively to exon 9 to promote the generation of PKM2 (Fig. 3A).[12] To verify a role for hnRNPA1 in PKM2-mediated regulation of glucose metabolism we used siRNA to down-regulate hnRNPA1 expression in glioma cells. Here, HNRNPA1 is linked to central nervous system cancer.