Currently there are no approved IgGs with amino acid-modified increased Fc effector function, although there are two such Fc-modified, increased Fc effector function IgGs in late stage clinical trials, the anti-CD19 mAb, Mor208 (Morphosys, Xencor), in phase II/III clinical trials for treatment of B cell malignancies (NCT02763319), and the anti-ERBB2 (HER2) mAb, margetuximab (Merck, Macrogenics), in phase III clinical trials for breast cancer (NCT02492711). This evidence concerns the gene ERBB2 and breast cancer.