Of the 2–5 bp deletions in tumours with biallelic RNASEH2B loss, more than half (57%) were 2 bp deletions, which were predominantly at STR and SNMH sequences and substantially enriched for the TNT motif (Extended Data Fig. 8b, c), consistent with the ID-TOP1 mutational signature. Here, RNASEH2B is linked to neoplasm.