Figure 13: Computer result of the maturation process of T-lymphocytes. First a naïve T-lymphocyte ( , green) in bone marrow or thymus undergoes T-cell receptor rearrangement ( -selection). T-cells with high affinity to self-peptides MHC ( , black) are eliminated (negative selection), whereas T-cells with T cell receptors that are able to bind self-peptides MHC molecules with at least a weak affinity ( , blue and , red) survive (positive selection) and circulate in the peripheral lymphatic system. The matured T-lymphocyte, recognizing the antigen by high affinity to the antigen-loaded MHC ( , red), transforms into an effector cell and proliferates. Glimpses at generation at and . Left: probabilities of finding individuals of T lymphocytes ( ). Upper right: extinction probability as a function of generations . Lower right: average of T lymphocytes as a function of generations . Parameter values and their change during the dynamics (a) (b) (c) : maximal total number ; , , , , , , , , , , , , , , .