Overall the majority of the SMG gene mutations are caused by azathioprine signature 32 (66.2%): 24.4% are due to UVR driven signature 7; 7.8% are caused by clock-like mutational signatures20 (signatures 1 and 5) and the remaining 1.7% by APOBEC related signatures 2 and 13, suggesting the driving mutational processes responsible for the initiation and progression of the tumours in our sample set are due to a combination of UVR and azathioprine exposure (Fig. 3c and Supplementary Data 18). This evidence concerns the gene CLOCK and neoplasm.