POU domain class 2-associating factor 1 is a protein that in humans is encoded by the POU2AF1 gene. POU2AF1 has been shown to interact with POU2F1 and SIAH1. POU domain class 2-associating factor 1 is a protein that in humans is encoded by the POU2AF1 gene.Transcriptional coactivator that specifically associates with either OCT1 or OCT2. It encourages the OCT1 mediated promoter activity and to a lesser extent, that of OCT2. It has no intrinsic DNA-binding activity. It recognizes the POU domains of OCT1 and OCT2. It is necessary for the response of B-cells to antigens and required for the formation of germinal centers.