Studies have shown a positive correlation between elevated infiltration of cytotoxic CD8+ T cells into tumors and improved prognosis.[13] Unsupervised clustering of CD8+ T cells identified in total CD45+ cells isolated from the lungs of tumor‐bearing mice revealed the presence of four clusters of CD8+ T cell subsets with distinct transcriptomic profiles (Figure 2A–C). Here, CD8A is linked to neoplasm.