In the multivariate analysis, only the lower frequency of CD4- iNKT cells could predict higher incidence of acute GVHD in patients receiving BM and PBSC grafts and higher CD4- iNKT cell ex vivo expansion capacity was associated with lower rates of grade 2–4 GVHD in patients receiving PBSC grafts (165). The gene discussed is CD4; the disease is acute graft versus host disease.