IFNG and gastric cancer: Epstein Barr Virus (EBV)-positive gastric cancers in particular have relatively high levels of CTLs and IFN-γ [62] and indeed, single agent pembrolizumab yielded an immense ORR of 100% in Korean patients with advanced EBV-positive gastric cancer [63] suggesting that EBV positivity may be an important predictive biomarker in gastric cancer.