ChIP-seq from this cell line provides both an assessment of IRF4 occupancy in a distinct transcription factor context, and an additional control for the specificity of the SPIB antibody since the strong expression of PU.1 relative to SPIB would be expected to result in a reversal of the cistrome sizes in comparison to the two DLBCL cell lines. This evidence concerns the gene SPI1 and diffuse large B-cell lymphoma.