Testicular germ cell cancer (TGCC) develops from pre-malignant germ neoplasia in situ (GCNIS) cells. GCNIS originates from fetal gonocytes (POU5F1+ /MAGE-A4− ), which fail to differentiate to pre-spermatogonia (POU5F1− /MAGE-A4+ ) and undergo malignant transformation. | The oncogene Gankyrin is expressed in testicular cancer and contributes to cisplatin sensitivity in embryonal carcinoma cells