In tumor subgroups based on SOX2 and SFRP2 transcript levels in the TCGA and The Chinese gliomas genome atlas (CGGA) glioblastoma datasets [23], the respective SFRP2high/SOX2low subgroups were enriched with mesenchymal subtype tumors (Fig. 3H, I). Here, SFRP2 is linked to neoplasm.