ERBB2 and invasive breast carcinoma: Library 1 (Lib_1) was prepared from the human breast cell line C5.2, which over-expresses the oncogene ERBB2, and library 2 (Lib_2) was prepared from a pool of 5 invasive breast carcinoma samples that stained positively for ERBB2 according to immunohistochemistry analysis (Table 1).