B7-h4 expression in a range of breast pathology: correlation with tumor T-cell infiltration.

B7-H4, a member of the B7 family, is involved in the regulation of antigen-specific immune responses. Its expression in a range of breast pathology and correlation to the number of CD3 and CD8 tumor infiltrating T-lymphocytes in invasive carcinomas were explored. The proportion of B7-H4 positive cells, staining pattern, and intensity were evaluated within diagnostic groups (normal and benign lesional, potentially premalignant and in situ carcinoma, and invasive carcinoma) on archival tissue blocks by immunohistochemistry.