ERBB2 and neoplasm: In general, associations between p53 status and clinicopathological factors were similar for luminal A-like and luminal B-like/HER2− subtypes, in which p53 positivity was associated with more aggressive tumor features such as higher grade, higher levels of proliferation (indicated by KI67 positivity), and higher frequencies of positive staining for basal markers (CK5/6 and EGFR).