However, tumor inhibition was even stronger in WT animals whose bone marrow had been replaced with that of PPARα KO mice (Figure 4A) as well as in PPARα deficient hosts (Figure 4A and 4C), again suggesting that not only is PPARα necessary for tumor growth, but that its absence confers a tumor suppressor activity on neutrophils. The gene discussed is PPARA; the disease is neoplasm.