TKT and central nervous system cancer: Previously, the HSV-TK+GCV enzyme-prodrug ablation system has been utilized to target such neural cell types as: C17.2 immortalized mouse cerebellar NPCs, C6 rat gliomas, GFAP-expressing mouse dendritic NSCs, endogenous murine NG2+ pericytes and OPCs, murine GFAP+ reactive astrocytes, human ESC-derived NPCs, and hiPSC-NPCs (Morshead et al., 2003; Faulkner et al., 2004; Li et al., 2005; Uhl et al., 2005; Pu et al., 2011; Tieng et al., 2016; Hesp et al., 2018; Kojima et al., 2019).