AICDA and mismatch repair cancer syndrome 1: Wang et al. recently stratified ovarian cancer into 7 subgroups within histotypes based on their diverse DNA repair deficiency-related signatures, which were characterized by mutation signatures associated with mismatch repair deficiency, the AID/APOBEC family of cytidine deaminases, age at diagnosis, the prevalence of foldback inversion structural variations, the prevalence of duplications or deletion rearrangements and homologous recombination deficiency.