TTBK2 and central nervous system cancer: For examples, Zheng et al. found that circular RNA TTBK2 (circ-TTBK2) could promote glioma malignancy via modulating miR-217/HNF1β/Derlin-1 pathway 33; Chen et al. revealed that the expression of circPTN was markedly elevated in glioma, circPTN might act as a tumour promoter through sponging miR-145-5p/miR-330-5p 34; Cao et al. showed that hsa_circ_0037251 could function as an oncogenic gene via a hsa_circ_0037251/miR-1224-3p/mTOR axis in glioma, and these potential biomarkers might be therapeutic targets 35.