ERBB2 and neoplasm: Tetraspecific antibodies such as FL518 and CRTB6, simultaneously targeting EGFR, HER2, HER3, and VEGF, effectively suppress their respective signaling pathways in vitro and in vivo, disrupt HER–MET cross-talk, and outperform “two-in-one” and several bispecific constructs across multiple tumor models (269).