ARID1A and cancer: When the grade of luminal formation was scored as 0–3 (0, none; 1, <10%; 2, 10%–50%; and 3, >50% of cancer cell nests), four of five ARID1A-lost EBVaGCs showed grade 2–3, while five of seven ARID1A-preserved tumors showed grade 0–1 (p = 0.0659, Wilcoxon rank sum test).