Notably, the PALLAS (Gnant et al., 2022) and Penelope-B (Loibl et al., 2021) trials revealed no benefit in HR+/HER2- early-stage breast cancer, but the NATALEE (Slamon et al., 2024) and MonarchE (Johnston et al., 2023) trials reported divergent findings. Here, ERBB2 is linked to breast cancer.