Receptor revision in T cells: an open question?

During lymphocyte development, both B and T cells assemble antigen receptor variable region genes from germline gene segments, allowing the expression of unique receptors in each clonally derived lymphocyte. Previously, it was shown that in certain cases, progenitor and immature B cells are capable of editing their receptors to a new specificity on encounter with self-antigens. Although the existence of such a process in T cells remains controversial, recent studies suggest that mature T cells are able to similarly revise their receptors in the periphery.