CCL5 and CCL4 were specifically expressed in B-0 (Fig. 6D, F), which activate antigen presentation pathways and PD-L1/PD-1 immune checkpoints in cancer to recover the adverse effect of low CCL5 expression reducing the recruitment efficiency for cells in immune killing cascades (e.g., cDCs and CTLs). The gene discussed is CCL4; the disease is cancer.