ERBB2 and breast cancer: Moreover, the FcγRIIIA affinity enhanced mutant (featuring L235V, F243L, R292P, Y300L, and P396L) has been adopted for the development of Margetuximab, recently demonstrated superior PFS compared to trastuzumab in the SOPHIA trial (NCT02492711) [385] and is now FDA approved for the treatment of metastatic HER2 positive breast cancers.