PDCD1 and neoplasm: The levels of signal transducer and activator of transcription 3 (STAT3), phosphorylated‐STAT3 (p‐STAT3), Janus kinase 1 (JAK1), phosphor‐Janus kinase‐1 (p‐JAK1), and PD‐1 in tumor tissues were measured using Western blot (WB).