WASP and N-WASP regulate in vivo homing of B cells. (A) Splenic B cells from WT, WKO, and cDKO mice were labeled with tetramethylrhodamine isothiocyanate (WT, red) or CFSE (WKO or cDKO, green) and mixed at a 1:1 ratio before IV injection to WT mice. (B) Competitive homing of WT and WKO or cDKO B cells. Spleen, peripheral and mesenteric lymph nodes, Peyer patches, BM, and blood of recipient mice were harvested after 12-15 hours, and the percentage of WKO and cDKO B-cell homing relative to WT cells was determined. (C) Competitive homing of WKO (tetramethylrhodamine isothiocyanate–labeled) and cDKO (CFSE-labeled) B cells. Shown are averages ± SD of combined data from 2 experiments including 4 mice per group. Dashed line represents the input percentage. *P < .05 compared with WKO.