Transcription factor that binds to the octamer motif (5'- ATTTGCAT-3') and activates the promoters of the genes for some small nuclear RNAs (snRNA) and of genes such as those for histone H2B and immunoglobulins. Modulates transcription transactivation by NR3C1, AR and PGR. {ECO:0000269|PubMed:10480874, ECO:0000269|PubMed:1684878, ECO:0000269|PubMed:7859290}. (Microbial infection) In case of human herpes simplex virus (HSV) infection, POU2F1 forms a multiprotein-DNA complex with the viral transactivator protein VP16 and HCFC1 thereby enabling the transcription of the viral immediate early genes. . This is the function of Ensembl gene identifier ENSG00000143190 (POU2F1, POU class 2 homeobox 1).