LTC4, LTD4, and LTE4 contribute to allergic airways reactions such as asthma, certain non-allergic hypersensitivity airways reactions, and other lung diseases involving bronchoconstriction by contracting these airways and promoting in these airways inflammation, micro-vascular permeability, and mucus secretion; they likewise contribute to various allergic and non-allergic reactions involving rhinitis, conjunctivitis, and urticaria (see LTC4, LTD4, and LTE4). Certain of these peptide-leukotrienes have been shown to promote the growth of cultured human breast cancer and chronic lymphocytic leukemia cell lines thereby suggesting that ALOX5 may contribute to the progression of these diseases.