ERBB2 and neoplasm: The most common tumor subtype was HR+/HER2− (19,767/27,869; 70.9%), followed by HR−/HER2− (5355/27,869; 19.2%), HR+/HER2+ (1930/27,869; 6.9%), and HR−/HER2+ (817/27,869; 2.9%).