MRE11 and hepatocellular carcinoma: Because three of the eight missense mutations located in the binding domain of Nbs1, we examined Mre11 nuclear staining by performing IHC and IF assays (when frozen tissue was available) on all tumors with NBS1 mutations to determine whether the NBS1 mutations have functional consequences on the binding of Nbs1 to Mre11; 10 HCC and 10 ICC cases without NBS1 mutations served as controls.