Taken together, these studies in mice and men indicate that α4β1 and αMβ2 are the major eosinophil integrins mediating cell adhesion, with α4β1 largely responsible for arrest of blood eosinophils on VCAM-1 in vessels of the asthmatic lung, with a more minor contribution by αMβ2; whereas activated αMβ2, by interacting with periostin and possibly other ligands, is involved in subsequent eosinophil recruitment to and persistence in the ECM of the bronchi in asthma. Here, POSTN is linked to asthma.