抗體，也叫免疫球蛋白（Ig），是一種能特異性結合抗原的糖蛋白，而抗原是在易感染動物體內引發抗體產生的物質。在體內，抗體是由于外源性分子的侵襲而產生的。抗體以一個或者多個Y字形單體存在，每個Y字形單體由4條多肽鏈組成，包含兩條相同的重鏈和兩條相同的輕鏈。輕鏈和重鏈是根據它們的分子量大小來命名的。Y字形結構的頂端是可變區，為抗原結合部位。任何一個抗體的輕鏈都可以分為κ或λ型（基于小分子多肽結構上的差異），每一個抗體的重鏈則決定了它的類或型。
The protein encoded by this gene is a cytokine that belongs to the tumor necrosis factor (TNF) ligand family. This protein preferentially induces apoptosis in transformed and tumor cells, but does not appear to kill normal cells although it is expressed at a significant level in most normal tissues. This protein binds to several members of TNF receptor superfamily including TNFRSF10A/TRAILR1, TNFRSF10B/TRAILR2, TNFRSF10C/TRAILR3, TNFRSF10D/TRAILR4, and possibly also to TNFRSF11B/OPG. The activity of this protein may be modulated by binding to the decoy receptors TNFRSF10C/TRAILR3, TNFRSF10D/TRAILR4, and TNFRSF11B/OPG that cannot induce apoptosis. The binding of this protein to its receptors has been shown to trigger the activation of MAPK8/JNK, caspase 8, and caspase 3. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provi
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