ACM derived from OGJ patients with late-stage tumours decreased the expression of PD-1 on the surface of CD4+ T cells (untrx: 78.63 ± 1.5 vs. late-stage: 72.32 ± 3.7%, p = 0.06) compared with untreated cells (Fig. 2A). Here, PDCD1 is linked to neoplasm.