We performed qRT-PCR and western blotting in six GBM cell lines and found that MAPK6P4 expression was significantly upregulated in GBM cell lines, especially in U251 and U373 cells (Fig. S1.1 a); however, no significant changes were detected in mRNA and protein expression of the parental gene MAPK6 (Fig. S1.1 b, c). This evidence concerns the gene MAPK6P4 and glioblastoma.