Biological process

regulatory T lymphocyte differentiation, regulatory T-cell differentiation, regulatory T-lymphocyte differentiation, suppressor T cell differentiation, suppressor T lymphocyte differentiation, suppressor T-cell differentiation, suppressor T-lymphocyte differentiation

The process in which a relatively unspecialized T cell acquires specialized features of a regulatory T cell. Regulatory T cells control or suppress immune responses through a variety of mechanisms and subsets include the CD4+CD25+ cell type as well as certain CD8+ cell types.

regulatory T cell development

Note that immunologists typically use the word 'development' to refer to cells of B or T cell lineages undergoing the process that GO describes as 'cell differentiation'.