To this end, we identified cancer cell lines, in which WRN KO was performed and the cell’s viability was validated (i.e. viability assays were performed on cell lines using a single sgRNA targeting WRN instead of a pooled sgRNA KO screen) and analysed whether MSI cell lines that harboured KMT2DLOF alterations showed more consistent lethal effects upon WRN KO compared to KMT2DWT MSI cell lines. Here, WRN is linked to cancer.