POU5F1 and neoplasm: OCT4, as an important transcription factor, participates in regulating self‐renewal and pluripotency in undifferentiated embryonic stem cells.24 This protein has gradually become a hopeful biomarker for the diagnosis of many tumors.25 As previously mentioned, OCT4 participates in tumorigenicity and tumor progression in many somatic cell cancers, including esophageal, bladder, prostate, gastric, and non‐small‐cell lung cancers.