KRAS and neoplasm: Previous studies have shown that CBX4 functions as a proto-oncogene during tumorigenesis.21 In this study, we performed CBX4 IHC staining on the previous tumor samples,21 and found that a subset of LUAD patients had high CBX4 expression but there were also a significant number of LUAD cases with low CBX4 expression, leading to a worse prognosis under the background of Kras mutation, restricted to stage III (Supplementary Fig. 14).