CSF2 and chronic obstructive pulmonary disease: Given the known role of the PI3K pathway in the hypoxic upregulation of degranulation from GM-CSF–primed neutrophils, and the aberrant chemotaxis of neutrophils from patients with COPD, which could be corrected by PI3K inhibition (30), we explored whether inhibition of PI3K signaling pathways modulated the hypoxic response of PAF-primed neutrophils using PI3K isoform–selective small molecule inhibitors.