Immunohistochemistry of human HCC. Serial sections from the paraffin-embedded tissue microarray blocks were used to stain for the CSC markers CD44, CD90, CD133, epithelial cell-adhesion molecule (EpCAM), and alpha-fetoprotein (AFP). Magnification:×100. Negative controls for rabbit monoclonal antibodies (CD90 and CD133) and mouse monoclonal antibodies (CD44, EpCAM, and AFP) are shown for each section.