抗体，也叫免疫球蛋白（Ig），是一种能特异性结合抗原的糖蛋白，而抗原是在易感染动物体内引发抗体产生的物质。在体内，抗体是由于外源性分子的侵袭而产生的。抗体以一个或者多个Y字形单体存在，每个Y字形单体由4条多肽链组成，包含两条相同的重链和两条相同的轻链。轻链和重链是根据它们的分子量大小来命名的。Y字形结构的顶端是可变区，为抗原结合部位。任何一个抗体的轻链都可以分为κ或λ型（基于小分子多肽结构上的差异），每一个抗体的重链则决定了它的类或型。
This gene has been reported in PMID 9403053 as one of several tumor-suppressing subtransferable fragments located in the imprinted gene domain of 11p15.5, an important tumor-suppressor gene region. Alterations in this region have been associated with the Beckwith-Wiedemann syndrome, Wilms tumor, rhabdomyosarcoma, adrenocortical carcinoma, and lung, ovarian, and breast cancer. Alignment of this gene to genomic sequence data suggests that this gene resides on chromosome 2 rather than chromosome 11. [provided by RefSeq, Dec 2008]
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