To determine whether hematopoietic (myeloid) or nonhematopoietic 12/15-LOX expression contributed to allergic asthma severity, we created reciprocal bone marrow chimeras in which either the hematopoietic or the nonhematopoietic compartment expressed 12/15-LOX, as well as control chimeras in which both compartments (analogous to WT mice) or neither compartment (analogous to Alox15−/− mice) expressed 12/15-LOX. Here, ALOX15 is linked to allergic asthma.