CPA4 and central nervous system cancer: hsa_circ_0082375 (chr7: 129950626–129964020), derived from the carboxypeptidaseA4 (CPA4) gene, has been uncovered to be upregulated in glioma tissues of 73 patients [9], whereas the underlying mechanism of hsa_circ_0082375 in glioma has not been clearly explained yet.