Slc44a2 is essential for neutrophil recruitment at the vessel wall following endothelial activation. Intravital microscopy was performed on mesenteric venules of mice deficient in Slc44a2 protein (SLC44A2 KO mice) after intraperitoneal histamine challenge. (A) Quantification of neutrophil rolling on mesenteric venules in wild-type (WT) and SLC44A2 KO mice (wild-type, orange circles, n = 7 venules in 3 mice; SLC44A2 KO, green circles n = 8 venules in 3 mice). (B) Representative images showing reduced neutrophil recruitment in mesenteric venules of SLC44A2 KO mice after staining of endogenous rolling neutrophils by infusion of an Alexa Fluor 660-anti-Ly6g antibody (bars represent means; *P < .05). Scale bars, 100 µm.