As limitations, the small sample size, the heterogeneous patient population, missing QoL data during follow-up and the relatively limited follow-up time on this cohort of patients need to be acknowledged because they limit subgroup analyses and may affect the interpretation of long-term outcomes, and further studies are warranted to define the optimal role of HER3-DXd in patients with LMD. Here, ERBB3 is linked to Langer mesomelic dysplasia.