Contrasting and more coherent to our data, the inhibition of inositol 1,4,5-trisphosphate 3-kinase B (Itpkb), a negative regulator of Ca2+ influx, leads to an increase of intracellular Ca2+ in donor T cells, protecting mice from acute and chronic GVHD while maintaining a graft-versus-tumor-effect (11). The gene discussed is ITPKB; the disease is graft versus host disease.