PDCD1 and neoplasm: Within the combination treatment groups of anti-PD-1 and carbo/pax, the cytokines positively correlating with tumor burden were G-CSF (0.84700, p = 0.0334), IL-9 (r = 0.8174, p = 0.0470), and CXCL9, also known as MIG (r = 0.9072, p = 0.0125).