CD8A and melanoma: In melanoma, a variety of intratumoral microorganisms (especially Lachnoclostridum) can increase the infiltration of CD8+ T cells in the immune microenvironment, and are positively correlated with the levels of chemokines CXCL9, CXCL10, and CCL5, which is helpful to improve immunotherapy and improve the survival rate of patients [176].