Fig. 3.

Graphical representation of attempts to encompass structural and sequence similarity in a suitable clustering distance metric that aims to capture epitope specificity. Binding of six fictional TCRs to three fictional epitopes is depicted on the upper left side. The TCRs are shown in shades of green, purple and red, while epitopes are coloured in green, orange and light purple. If primary sequences of the TCRs are known, sequence comparison can be used to create a distance matrix TCR distance matrix. The matrix could then be used to cluster individual TCRs together based on their sequence similarity, with the goal of clustering by biological similarity i.e. epitope response. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)