An analysis of variable importance revealed MLH1 expression as the feature most highly associated with the classification outcome, in line with the frequent inactivation of the MLH1 gene in MSI-H CRC (Cunningham et al., 1998; Herman et al., 1998; Kane et al., 1997; Kuismanen et al., 2000) (Figure 1—figure supplement 1A). Here, MLH1 is linked to colorectal carcinoma.