推测T细胞库（T cell repertoire)中多样性在1010以上，其多样性的原因与Ig相似，主要有以下几方面。
1.胚系中有众多的V、D和J基因片段 尽管TCRα和β基因中V基因片段数比Ig基因少，但J基因片段明显比Ig基因为多，如小鼠中约50～100个Jα和至少12个Jβ基因片段，而IgH和κ链基因座中J基因片段各只有4个。
2.连接处连接的多样性 与IgVDJ连接的多样性相似。
3.N区的插入 N区插入在Ig基因重排中只发生在重链基因，而TCRα和β链基因均可发生N区的插入。此外，在TCRα和β链基因中都发现一种称之为“易变性”（flexibility)的现象，如有一个以上Vα基因3′端可以连接到Jα片段。
4.TCRα与β链的随机配对 人TCRαβ库多样性可推算为：α链（Vα（100)×Jα（100))×β链（Vβ（100)×Dβ（2)×Jβ（14))=2.8×107，这种多样性尚未包括N区插入所扩展的多样性。
参考文献
1.Cunningham B A,et al.Neural cell adhesion molecule:structure,immunoglobulin-like domain,cell surface modulation,and alternative RNA splicing.Science,1987;236:799
2.Flanagan JG,et al.Arrangement of human immunoglobulin heavy chain constant region genes implies evolutionary duplication of a segment containing γ,ε and α genes. Nature,1982;300:709
3.Hood L,et al.T cell antigen receptor and the immunoglobulin supergene family. Cell.1985;40:225
4.Hunkapiller T,et al.The growing immunoglobulin gene superfamily.Nature,1986;323: 15
5.Nossal GJV.Triumphs and trials of immunology in the 1980s.Immunol Today,1988;9: 286
6.Romagnanni S.Regulation and deregulation of human IgE synthesis.Immunol Today,1990;11(9):316
7.Sims JE,et al.cDNA expression cloning of the IL-1 receptor,a member of the im-munoglobulin superfamily,Science,1989;241:585
8.Shimizu A,et al.Organization of the constant region gene family of the mouse im-munoglobulin heary chain.Cell,1982;28:499
9.Tucker PW.Transcriptional regulation of Igm and IgD. Immunol Today,1985;6:181
10.White JM,et al.Viral receptor of the immunoglobulin superfamily.Cell,1989;58:725
11.Williams AF.A year in the life of immunoglobulin superfamily.Immunol Today, 1987;8:298
12.徐人尔综述，赵寿元审校.NF-κB与基因调控.国外医学分子生物学分册.1993；15（6)：2511
