DMRT1 and germ cell tumor: Furthermore, analysis of copy number variation analysis showed DMRT1 loss at chromosome 9, possibly the trigger of teratoma formation, and 12p gain, which we have previously reported to be a marker of aggressive non-germinomatous germ cell tumors (NGGCTs) of the central nervous system (CNS) and seen in approximately 30% of cases [6] (Figure 5b).