Of note, the expression of SLC22A17 was increased in the neuronal tumors LGG, GBM, and PCPG and in THCA, which also showed high expression of LCN2 and MMP9. The downregulation of SLC22A17 observed in some tumors could be related to cancer survival and proliferation by affecting the cancer iron metabolism. The gene discussed is MMP9; the disease is neuronal tumor.