Based on a mouse model study of pro-B cells, binding of Signal transducer and activator of transcription 5A and 5B (STAT5A or STAT5B), activated in response to Interleukin-7 (IL7) signaling to the BRWD1 gene promoter, results in the inhibition of Bromodomain and WD repeat-containing protein 1 (BRWD1) transcription. STAT5 binding coincides with the appearance of H3K27me3 marks at the BRWD1 promoter, a marker of repressed chromatin (Mandal et al. 2015). STAT5 is able to recruit the polycomb repressive complex (PRC2) to genes silenced in response to IL7 signaling (Mandal et al. 2011), which may explain the H3K27me3 marks at STAT5-bound BRWD1 promoter.

In pre-B cells, in contrast to pro-B cells, IL7 signaling is downregulated, which induces BRWD1 transcription. BRWD1 enhances the recruitment of the recombinase complex V(D)J recombination-activating protein 1: V(D)J recombination-activating protein 2 (RAG1:RAG2) to the immunoglobulin kappa locus, thus promoting V(D)J recombination - a key event in B lymphopoiesis (Mandal et al. 2015).