ERBB2 and maternal uniparental disomy of chromosome 20: However, neither the treatment with lapatinib of pre-treated HER2-negative MBC patients with HER2-positive or EGFR-positive CTCs [245,246] nor the treatment with TDM-1 of pre-treated HER2-negative MBCs with ERBB2 amplified CTCs in the CirCe T-DM1 trial [247] resulted in an objective benefit.