To evaluate the intensity of CHST4 expression, we scored the IHC staining results as a percentage of CHST4 immunoreactivity in mesothelioma cells; since CHST4 localizes to the cytoplasm [8], the fraction of cytoplasmic CHST4-positive stained mesothelioma cells was scored after examining six high-power fields (40×) in one tissue section for each case (Figure 5A,B). Here, CHST4 is linked to mesothelioma.