Hye Ryun Kim^1*‡ , Su-Myeong Park^2*, Sang-Uk Seo^2,3, Inkyung Jung¹, Hong In Yoon¹, Dmitry I. Gabrilovich⁴, Byoung Chul Cho^1,5‡, Seung-Yong Seong^2,3‡, Sang-Jun Ha^6‡ , and Je-In Youn <sup>2,3,6‡§

1</sup> Yonsei University College of Medicine Seoul, Korea
² Seoul National University College of Medicine Seoul, Korea
³ Seoul National University College of Medicine Hongcheon, Korea
⁴ Wistar Institute Philadelphia, Pennsylvania
⁵ JEUK Co., Ltd. Gumi City, Korea and
⁶ Yonsei University Seoul, Korea

^*These authors contributed equally to this work.
^‡Joint principal investigators who contributed equally to this study.
^§Corresponding author

Immune checkpoint inhibitors (ICIs) have emerged as a promising treatment modality for patients with non-small cell lung cancer (NSCLC). However, ICI monotherapy has a relatively low response rate (approximately 20-50% in patients with NSCLC) (1), and consequently it is important to develop predictive biomarkers of response to inform clinical decisions regarding ICI use. Although PD-L1 expression on tumor cells is currently used as a predictive determinant for anti-PD-1 therapy responses, the accuracy of this test is relatively poor. Therefore, better predictive biomarkers for anti-PD-1 therapy in patients with NSCLC are needed.