Lastly, comparing the somatic alterations between primary and post-NACT residual tumors, we found substantial loss of ERBB2 amplification among the ERBB2+ residual tumor samples after NACT, which has also been seen in other studies.45,46 We also found decrease of TOP2A and PIK3CA alterations among ERBB2+ residual tumors, and a significant increase of PTEN loss among TNBC residual tumors, consistent with previous reports.47,48,49 These alterations point to alternative pathways that could be potential therapeutic targets. Here, ERBB2 is linked to neoplasm.