ERBB2 and neoplasm: Our findings were further verified by reacting other tumor-homing peptides like D-Lys6-GnRH and Fmoc-HER2-BP1 (LTVSPWY, a heptapeptide known for its activity against erbB2) with HATU/DIPEA and characterizing the final products by ESIMS and 1H NMR spectroscopy where the same aminium side product was also recorded.