CXCL12 and WHIM syndrome: Therefore, we explored whether mRNA electroporation of CXCR4, including the WHIM syndrome naturally occurring GOF mutated variant CXCR4R334X (12), could be utilized to improve NK cell in vitro migration toward its ligand stromal-derived factor-1α (SDF-1α) and in vivo homing to BM compartments in mice.