BCL6 and neoplasm: Given the expected feedback between NF-κB and NF-κB control genes, we focused on BCL6, an oncogenic repressor30 and KLF6, a transcriptional activator and tumor suppressor.11 Copy number analysis for KLF6 (10p15) and BCL6 (3q27) revealed heterozygous deletions of KLF6 in 74.5% of tumors, but homozygous deletions in only 0.4% (Figure 2a).