Recent germline sequencing research has shown the presence of CD109 in paediatric germ cell tumours arising from gonadal tissues, and several subtypes of paediatric germ cell tumours are shared with testicular germ cell tumours that arise after puberty, for example: teratoma, yolk sac tumour, embryonal carcinoma, and choriocarcinoma (74). The gene discussed is CD109; the disease is choriocarcinoma.