Using flow cytometry to analyze CD8+ T cells, PD-1 and myeloid-derived suppressor cells (MDSCs) in TME after distal tumor treatment, the results showed that the combination therapy group had the highest percentage of CD8+ T cells, the highest PD-1 expression, and the lowest ratio of MDSCs, suggesting that nanodrug delivery systems enhanced the systemic antitumor adaptive immunity generated by the combined application of PDT and ICB therapy (Fig. 4F). The gene discussed is PDCD1; the disease is neoplasm.