In subgroup analyses, there were strong position associations with punctate necrosis (pre/perimenopausal women), detection by physical exam (postmenopausal women), architectural patterns other than the main types (breast-conserving surgery [BCS]), and DCIS margins (ipsilateral cases), and inverse associations with HER2 positivity (BCS) and microcalcification (mastectomy); however, the associated confidence intervals were mostly very wide. The gene discussed is ERBB2; the disease is ductal breast carcinoma in situ.