Here, in a cohort of patients receiving DLI after alloHSCT, we longitudinally assessed the TCR repertoire via the deep sequencing of the TCR beta chains of sorted CD4+CD25+CD127low Treg cells and sorted CD4+ Tcon cells while observing the emergence and clinical course of GVHD during a study period of 36 months post DLI. Here, CD4 is linked to graft versus host disease.