Higher levels of CD4 + T lymphocytes, CD8 + T lymphocytes, CD45 + PD-1 + lymphocytes, CD3 + PD-1 + T cells, CD3 + CD4 + PD-1 + T cells, CD3 + CD8 + PD-1 + T cells and CD45 + Tim-3 + lymphocytes were found in peritoneal neoplasms group than normal control (the p value was respectively 0.004, 0.047, 0.046, 0.044, 0.014, 0.038 and 0.017). The gene discussed is PDCD1; the disease is peritoneal neoplasm.