CXCR4 and Werner syndrome: Taking advantage of a mouse strain that harbors the naturally occurring WS-linked heterozygous CXCR4S338X mutation (Cxcr4+/1013, +/1013)51–54, and of human BM samples from WS donors and clinical data from 19 WS patients, we investigated whether WS mutations affect the SSC landscape with a particular attention given to the bone fraction.