Primate lung neutrophils are released after plerixafor treatment. (a, Left) A schematic representation of the simultaneous blood sampling method used in the nonhuman primate model Macaca fascicularis. Arrows indicate the direction of blood flow (blue = venous blood entering the lung; red = arterial blood exiting the lung). X indicates the aorta and inferior vena cava sites of blood collection. Blood was sampled from the aorta and vena cava before s.c. injection of 0.5 mg/kg plerixafor and then at 1-h intervals for a total duration of 4 h. (b) Net neutrophil release from the lungs of two individual animals over a 4-h observation period.