Given (i) the effective role of Rac proteins in driving neutrophil migration and activity and (ii) that a dominant negative mutation in Rac2 is associated with human immunodeficiency [50], Alan Hsu and colleagues have tested the hypothesis whether reducing rac2 activity in zebrafish neutrophils would reduce immunological damage caused by systemic inflammation [51]. The gene discussed is RAC2; the disease is immunodeficiency disease.