Next, we assessed the clinical relevance of intra-tumorous PD1+ macrophages in GC patients (Tables 1 and 2), and found that the proportions of PD1+ macrophages determined by flow cytometry were significantly associated with disease progression in 26 GC patients (Fig. 1f, Table 1), and that the number of PD1+ macrophages determined by immunofluorescence staining was also significantly associated with disease progression in 15 GC patients (Fig. 1g, Table 2). This evidence concerns the gene PDCD1 and gastric cancer.