Figure 3. Central tolerance induction physiology (left panel) and neonate with Omenn syndrome and erythroderma (right panel, above) who was successfully treated by cord blood transplantation (below); (pictures kindly provided by H. Ott, Hannover, published in [16]). The thymic selection of T cells during the first decade of life produces millions of antigenically distinct T cells carrying a very diverse T-cell receptor (TCR) repertoire prepared to encounter millions of variants of microbial and other antigens. Some autoreactive T-cell clones are also generated. This selection process is called central tolerance induction.