To this end, a cohort of 4929 breast cancer patients, whose data are publicly available online, has been stratified into three groups (trichotomization) according to the expression levels of ERBB4, and the relapse-free survival probability in lower tercile versus upper tercile was evaluated during a follow-up period of 250 months after tumor resection (please refer to the “Material and methods” section for further details regarding relapse-free patients’ survival analyses). This evidence concerns the gene ERBB4 and breast cancer.