There have been some clinical studies exploring the corresponding biomarkers, such as PD-L1 expression (Powles et al., 2014), CD8+ T cell (Ghatalia and Plimack, 2019), tumor mutational burden (TMB) (Yarchoan et al., 2017), and microsatellite instability (MSI) (Dudley et al., 2016). The gene discussed is CD8A; the disease is neoplasm.