Accordingly, the interaction between ERK5 and PRPS1/2 was confirmed via co-immunoprecipitation assays using either exogenous ERK5 and PRPS1/2 in cultured U-87MG cells (Fig. 4B), in vitro assay (Fig. 4C) and endogenous ERK5 and PRPS1/2 in the glioma tissues (Fig. 4D). The gene discussed is PRPS1; the disease is glioma.