Interestingly, the circMMP9/miR-124 axis regulates the expression of EMT markers in glioma cells.61 In addition, hsa_circ_0088732, derived from the cyclization of Lcn2, accelerates glioma progression, migration, invasion, and EMT through the miR-661/RAB3D axis.62 circ-PTN is an oncogenic factor. This evidence concerns the gene PTN and central nervous system cancer.