Several studies showed that SPRY2 gene expression was downregulated and inhibited in prostate cancer, breast cancer, malignant glioma and other tumor types, leading to uncontrolled and overactivated mitogen-activated protein kinase/extracellular-regulated kinase (MAPK/ERK) signaling in tumor cells (7,18–20). This evidence concerns the gene WNK2 and malignant glioma.