The present invention relates to an immortalized human neural precursor cell line, NGC-407. The cell line has been established from human foetal tissue. The cell line has been immortalized using a retroviral vector containing the v-myc oncogene. The cell line is a neural progenitor cell line capable of differentiating into to astrocytes and neurons including dopaminergic neurons. NGC-407 cells are capable of migrating to glioblastoma tumours implanted into rat brains and form gap junctions with the tumour cells. NGC-407 cells expressing a suicide gene can be be used for delivering activated prodrugs in the form of activated nucleoside analogs to tumours.