ROI Auxilary Data Ordering

In the resource provided on tumor proliferation scoring, it says that "The standard guidelines [for selecting ROI] are to select an area that encompasses the most invasive part of the tumor, at the periphery and with highest cellularity." I notice that the ROI data has 3 different rectangular regions as well. Are we to assume that the ROI data has the most invasive region, the periphery region, and the region with highest cellularity, in a well-defined order?

No, this is not the case. The ROIs are not ordered in any way.