ERBB2 and breast cancer: In the context of the potential association of htid expression with the biology of human breast cancers of different subtype the immunohistochemical analysis revealed elevated htid expression in 81% of the luminal A type tumors (Figure 1A), in 20% of the cases of the luminal B type over expressing ErbB-2 and in 18% of tumors diagnosed as the HER-2 subtype (not shown).