Shows weak transcriptional activator activity. Detected at the mRNA level in several cancer tissues (breast, uterine cervix, lung, thyroid gland, esophagus, colon, urinary bladder, and glioma), but absent in normal tissues. Belongs to the POU transcription factor family. Class-5 subfamily. Could be the product of a pseudogene. Several pseudogenes of POU5F1 have been described on chromosomes 1, 3, 8, 10 and 12. Two of them, localized on chromosomes 8 and 10 have been shown to be preferentially transcribed in cancer tissues and may be involved in the regulation of POU5F1 gene activity in carcinogenesis.