MSI-H and EBV-positive GCs are thought to be mutually exclusive, with 0% of patients in the SNUH GC cohort and TCGA-STAD study having GC with both MSI-H and EBV.46,47 To understand this exclusivity, Kim et al.48 generated MSI-H status in the EBV-positive GC cell-line NCC24 by MLH1 knockout via CRISPR-Cas9. The gene discussed is MLH1; the disease is gastric cancer.