HIF-1α, ATP5β and CAIX expression have greater heterogeneity in HypoxiSense-positive tumors as compared to HypoxiSense-negative tumors.

Mean, standard deviation (SD), and coefficient of variance (CV) of staining were quantified by measuring positive pixel count in 20 representative regions of each tumor slice using Aperio version 9. Quantification of protein expression in each region was calculated by multiplying the staining intensity by the positive area percentage as described in materials and methods.