For example, BrM derived from SCLC have a higher occurrence rate of tumor‐infiltrating lymphocytes (TIL), and the density of CD45RO+ TIL is associated with improved OS in patients [571]; a population of CD8+ T cells expressing TOX was found in melanoma BrMs, with lower expression levels of immune checkpoint markers than those in primary tumor samples [572]. The gene discussed is CD8A; the disease is neoplasm.