Extended Data Fig. 5: Attention heatmaps of TITAN.

Exemplar attention heatmaps for three Transformer attention heads of TITAN (head #4, #10, #11) are shown across three different TCGA WSIs. Out of the 12 attention heads, we find that most attention heads focus on dense tumor regions, with certain attention heads such as head #10 focusing on tumor-adjacent stroma and head #11 focusing on non-tumor areas. Across different cancer types, while head #11 attends to tissue-specific morphologies such as peritumoral stroma in the thymoma WSI and the tumor-adjacent stroma and ducts in the BRCA WSI, we do observe that general morphological patterns such as tumor/non-tumor are conserved across tissue types.