First, during late fetal development on sensitive strain backgrounds DMRT1 acts as a tumor suppressor that promotes mitotic arrest and silences pluripotency genes including Sox2. Dmrt1 mutant germ cells form testicular teratomas with high incidence in mice of a susceptible strain background [20] and GWAS studies linking DMRT1 to human germ cell cancer suggest that DMRT1 may act analogously in human germ cells [21]. This evidence concerns the gene DMRT1 and malignant germ cell tumor.