Fig. 3

Mutation signatures in Indian OSCC and their suspected origin. Summary results of MutSpec-NMF and MutSpec-Compare analyses obtained on the 106 OSCC samples. a Mutation signatures obtained by NMF with a factorisation value of four. b Comparison of the four OSCC signatures (vertical axis) with 34 reference signatures (horizontal axis) using the cosine similarity method. The heatmap is color-coded according to the cosine value that ranges from 0 to 1. Only reference signatures with a significant match (cosine > 0.9) are labelled. c Number of mutations contributing to each of the four signatures identified, for each sample analyzed. d Average contributions of the four identified signatures to the mutation load of clustered samples and number of samples by cluster