NCT04873362 is a phase III randomized, double-blind, placebo-controlled clinical trial designed to assess the efficacy and safety of atezolizumab or placebo combined with T-DM1 in HER2-positive breast cancer patients at high risk of recurrence after neoadjuvant treatment (Hurvitz et al., 2022). The gene discussed is ERBB2; the disease is breast carcinoma.