For non-invasive breast cancer (ductal carcinoma in situ [DCIS] and lobular carcinoma in situ [LCIS]), the most common molecular subtype was luminal A (42.7%), followed by luminal B (20.8%), and the HER2 subtype (18.8%); the triple-negative subtype was least common (10.4%). Here, ERBB2 is linked to ductal breast carcinoma in situ.