MAPK is reported to induce 5-LOX activity inhuman polymorphonuclear cells and the Mono Mac 6 human monocytic leukemia cellline [34], and these findings may support the presenceof PPAR-independent effects of PPAR α and γ ligands.However, MAPK phosphorylation has not been observed in mast cells treated withthese PPAR ligands. This evidence concerns the gene PPARA and monocytic leukemia.