However, e.g. lumretuzumab, in combination with pertuzumab and paclitaxel, was not confirmed clinically relevant therapy for patients with HER3-positive, HER2-low breast cancer [89], although was demonstrated effective in HER2-low/ER+ mouse xenograft model in vivo when combined with pertuzumab and endocrine (fulvestrant) therapy [90]. This evidence concerns the gene ERBB3 and breast carcinoma.