PMS2 and neoplasm: Characteristics of hypermutated tumors included (i) dramatic increase in mutational load across the genome compared to the matched primary tumor, (ii) acquired mutations in mismatch repair (MMR) genes including MSH2, MSH6 and PMS2, as well as (iii) enrichment of a transversion signature (COSMIC signature 11) at recurrence, indicating the effects of alkylating agents such as TMZ.14