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The recent re-evaluation of the concept that CD4+T helper cell subsets are irreversibly differentiated lineages has become one of the most hotly debated issues in immunology. Here, four leaders in the field provide their thoughts on the complexities and controversies surrounding the functional plasticity of T cell subsets.
Understanding how memory T cells develop has important implications for vaccine design. Here,Nature Reviews Immunologyasks four leading researchers in this field their thoughts on the ontogeny and lineage relationships of memory T cells.