We found that there is no significant difference in the FECH expression between non-tumor and GBM tissues in the Cancer Genome Atlas (TCGA) dataset (Fig. 5a, top left panel), and its expression is significantly lower in GBM tissues compared with non-tumor tissues in the Repository for Molecular Brain Neoplasia Database (REMBRANDT) and Gravendeel datasets (Fig. 5a, top right two panels). This evidence concerns the gene FECH and neoplasm.