Indeed, in some old reports, the migratory capacity of peripheral blood neutrophils from patients with PCD (PCD PMN) toward N-formylmethionyl-leucyl-phenylalanine (fMLP), leukotriene B4 (LTB4) and complement component 5a (C5a) has been shown to be reduced (6, 7), whereas others reported unaffected chemotaxis of PCD PMN to the bacterial peptide fMLP or rather aspecific stimuli, such as zymosan (8, 9). This evidence concerns the gene C5AR1 and primary ciliary dyskinesia.