CID-5721353 is a B-Cell Lymphoma 6 Inhibitor (BCL6 inhibitor). disrupted BCL6/corepressor complexes in vitro and in vivo, and was shown to bind the critical site within the BTB groove. This compound could induce expression of BCL6 target genes and kill BCL6-positive DLBCL cell lines. In xenotransplantation experiments, the compound was non-toxic and potently suppressed DLBCL tumors in vivo. MW: 457.23. Purity ≥98% by HPLC