Tile origins.

SM  =  structured morphology; UM  =  unstructured morphology; HE  =  hematoxylin-eosin; IHC  =  immunohistochemistry; NS  =  nuclear staining; CS  =  cytoplasmic and/or membranous staining. A set of 27 VSs was used with different tissue origins and different IHC biomarkers in the NS and CS categories. The VSs with an asterisk correspond to different tissue pieces of the same VS (one tissue piece was blurred while the other was sharp). The CS category includes biomarkers with membranous expression (e.g., CD34 and VEGFR-1). A total of 4,000 blurred and 4,000 sharp tiles were selected for each combination of morphology and staining pattern by targeting specific regions in the VSs (as illustrated in Figure 2).