The studies presented here complement the comprehensive functional assessment with additional in vitro binding (HER2 relative cell binding and binding kinetics, FcγR cell and kinetic binding), additional aspects of effector and primary HER2 inhibition (ADCP, inhibition of HER2 signaling, inhibition of proliferation in gastric cancer cells, synergy with chemotherapeutic and HER2 internalization) as well as non-clinical pharmacology (tumor xenograft studies in breast and gastric cancer models) and toxicokinetic results. This evidence concerns the gene ERBB2 and gastric cancer.