ERBB2 and carcinoma: Likewise, ERBB2 amplification was reported in gestational trophoblastic disease (GTN) that is a rare group of tumors that were mostly benign and origin from placental villous and extravillous trophoblast cells [23,24,25] ERBB2 amplification and expression in combination with hyperploidy leads to a higher proliferation and more aggressive behavior including metastases and carcinoma [23].