Indeed, we demonstrated that HMGA expression is dependent on the state of differentiation of TGCTs: HMGA1 is overexpressed in seminomas, HMGA1 and HMGA2 are overexpressed in pluripotential embryonal carcinoma cells, and just HMGA2 is upregulated in YST, finally, the expression of both proteins is lost in mature adult tissue of teratoma areas [4,18]. This evidence concerns the gene HMGA1 and teratoma.