Several of these genes were recurrently (in up to 36% of gastric cancer cases) affected by CNVs and/or missense or frameshift mutations, with the most recurrently affected genes belonging to the TREX-2 complex (ENY2, MCM3AP, SEM1, CETN3) or having RNA/DNA helicase or endonuclease activity (SETX, AQR, DHX9, RNASEH2) (Supplementary Fig. 7c). Here, SEM1 is linked to gastric cancer.