Junctional diversity describes the
DNA sequence variations introduced by the improper joining of
gene segments during the process of
V(D)J recombination. This process of V(D)J recombination has vital roles for the
vertebrate immune system, as it is able to generate a huge repertoire of different
T-cell receptor (TCR) and
immunoglobulin molecules required for
pathogen antigen recognition by T-cells and B cells, respectively. The inaccuracies of joining provided by junctional diversity is estimated to triple the diversity initially generated by these V(D)J recombinations.