Representative sections of ERH mRNA expression as detected by non-radioactive in situ hybridization (ISH). A, D, and G: Hybridization with antisense ERH probe demonstrates ERH mRNA expression. B, E, and H: Hybridization with sense ERH probe serves as negative control for the specificity of the antisense probe. C, F, I: Hematoxylin-eosin staining of consecutive sections shown in ISH. ERH mRNA was clearly detectable in epithelial cells from invasive breast cancer (D, G), while a less abundant ERH mRNA expression could be detected in epithelial cells of normal breast tissue (A).