Because NK cells expanded from WHIM syndrome patients with CXCR4R334X had superior in vivo homing to the BM of immunodeficient mice, and because CXCR4R334X mRNA electroporated NK cells showed superior migration to SDF-1α in vitro, we next tested whether electroporation of CXCR4R334X in expanded NK cells from healthy human donors could be used as a strategy to improve their homing to the BM in NSG mice compared to non-transfected NK cell controls. Here, CXCL12 is linked to WHIM syndrome.