We detected 1,365 frameshift MSI events in the tumours predicted as MSI-H, with the most frequent incidences in DPYSL2 (12 cases), OR11G2 (9), SLC22A9 (9) and KIAA2018 (8), suggesting that the MSI events that recur in MSI-H cases (cf.Fig. 2) constitute a mutational signature that is leveraged by the predictive model for MSI categorization. This evidence concerns the gene SLC22A9 and neoplasm.