WHIM-CXCR4–expressing retrogenic T cells led to a delay in IgG antisera production. RAG1^−/− recipient mice (n = 5 per group) were reconstituted with retrogenic WT (rgWT) or WHIM (rgWHIM) T cells specific for OVA, as well as T-depleted splenocytes, and immunized with NP-OVA. The bars indicate anti-NP IgG titers in the sera at various time points after immunization. **P < .01; ***P < .001 (2-way ANOVA and Bonferroni posttests). n.s., not significant.