<qa>  What is the effect of OC000459 on cytokine secretionThe study will be a randomised, double blind, placebo controlled, crossover evaluation of the effect of OC000459 on cytokine secretion induced by nasal allergen challenge. Male subjects with a known history of allergic rhinitis and screening positive to allergen will be included. After dosing with OC000459 or placebo, nasal allergen challenge will be performed and measurements made in the nasal fluids. Nasal symptom scores will also be recorded. Safety parameters will be monitored throughout. 