Extended Data Fig. 3: Morphological correlates of intratumor heterogeneity of MSI.

a, Histological image of a test set patient who was genetically determined as MSI. b, Corresponding predicted MSI map for the image shown in a. Three regions are highlighted. Region 1 is a glandular region with necrosis and extracellular mucus; this region was predominantly predicted to be MSS. Region 2 is a solid, dedifferentiated region, which was predicted to be MSI. Region 3 contained mostly budding tumor cells mixed with immune cells, this region was strongly predicted to be MSI. Together, these representative examples show that different morphologies elicit different predictions and that these predictions can be traced back to patterns that are understandable for humans. Scale bar, 2.5 mm. This figure is representative of n = 378 patients in the DACHS cohort.