Furthermore, the co-occurrence of a TP53 p.I195T missense mutation in exon 6, although present at a lower abundance (0.9%) and may lead to a more aggressive tumor phenotype and poorer prognosis (Kelemen et al., 2018), our patient demonstrated robust antitumor activity with T-DXd, possibly due to its mechanism of delivering a potent cytotoxic payload directly to HER2-expressing cells and its unique bystander effect that improves efficacy even in heterogeneous tumors (Yver et al., 2020). The gene discussed is TP53; the disease is neoplasm.