ERBB2 and neoplasm: We further performed immunohistochemistry (IHC) staining with commercial tissue microarrays (HBreD140Su03 and HBreD077Su01) and found that RICH1 was more highly expressed in noncancerous tissue regions and weakly detected in tumor tissues, especially in tumors with high degree of malignancy, such as HER2-positive and TNBC samples (Fig. 1E–G).