BCL6 and lymphoma: GSK137 with an affinity for the BCL6 BTB–POZ domain of 10 nM (pIC50 = 8; Table 1) has a potency of the same order as BI3802 (<3 nM) but produced virtually no detectable reduction in proliferation, only minor derepression of BCL6 target genes and modest G1 cell cycle increases in lymphoma cell lines including DLBCL cell lines.