Arsenite has been demonstrated to repress constitutive activation of NFκB and COX-2 expression in human acute myeloid leukemia (HL-60) cells (Han et al. 2005), and pretreatment of arsenite attenuates benzo[a]pyrene cytotoxicity in a human lung adenocarcinoma cells by decreasing cyclooxygenase-2 levels (Ho and Lee 2002). Here, PTGS2 is linked to acute myeloid leukemia.