CD4 and neoplasm: More recently, Steven Rosenberg’s group found that tumour-infiltrating CD4+ Tregs expressed a distinct TCR repertoire that was enriched in tumours across several cancer types [83] by using deep TCR-sequencing to compare the TCR repertoires of tumour-infiltrating CD4+ Tregs and Tconvs with those of CD4+ T cell populations in autologous peripheral blood.