SLAMF8 levels in peripheral blood were negatively correlated with tumor purity (r=-0.363, P = 2.12 × 1014) and positively correlated with B cells (r = 0.672, P = 2.00 × 1055), CD8 + T cells (r = 0.418, P = 5.31 × 1019), CD4 + T cells (r = 0.625, P = 5.22 × 1046), macrophages (r = 0.563, P = 3.99 × 1036), neutrophils (r = 0.60, P = 7.52 × 1042), and dendritic cells (r = 0.679, P = 1.81 × 1057). The gene discussed is CD8A; the disease is neoplasm.