In some cases, the secreted bacterial effectors have not been identified: molecules secreted by L. reuteri were found to potentiate tumour necrosis factor (TNFα)-induced apoptosis in myeloid leukemia-derived cells by suppressing Nuclear Factor-kB (NF-kB) activation by inhibiting IkBa degradation, downregulating nuclear factor-kB (NF-kB)-dependent gene products and promoting apoptosis by enhancing MAPK activities including c-Jun N-terminal kinase and p38 MAPK15. The gene discussed is NFKB1; the disease is myeloid leukemia.