Fig. 2
From: γδ T cells: origin and fate, subsets, diseases and immunotherapy

The possible mechanisms of human γδ T development and fate decision in thymus. In circulation, the phenotypes of γδ T cells at least include naïve γδ T cells, IFNγ-producing γδ T cells (γδT1), IL-17-producing γδ T cells (γδT17), IFNγ/IL4-producing γδ T cells (γδNKT or CD56+γδT), very rare CD4+γδ T cells, and CD8+γδ T cells