CD8A and cancer: An increasing number of studies have found that the immune-related features of cancers such as the intensity of CD8+ T cell infiltrates, leukocyte fraction, T cell receptor (TCR) and B cell receptor (BCR) repertoire (Tang et al., 2016; Li et al., 2019; Zeng et al., 2019) were correlated with immunotherapeutic responsiveness in various cancers, including lung cancer, however, the immune-related features themselves alone are not a sufficient predictor of response to immunotherapeutic intervention (Riaz et al., 2017; Moya-Horno et al., 2018).