Unlike other antibodies, IgA can be secreted out in pairs, or a dimeric form called secretory IgA, which is literally two IgA antibodies attached together.

与其他抗不同，IgA可以以成对或二式分泌，也就是两个IgA连接在起。

The Jun (c-Jun, JunB, JunD) and Fos (c-Fos, FosB, Fra1, Fra2) proteins are components of the dimeric activator protein-1 (AP-1) transcription factor complex.

Jun (c-Jun、JunB、JunD) 和 Fos (c-Fos、FosB、Fra1、Fra2) 蛋白是二蛋白-1 (AP-1) 转录因子复合物的组成部分。

Now, IgA comes in subclasses—IgA1 and IgA2, IgA1 is found mainly in the serum while IgA2 is more often found in the mucus secretions, typically in its dimeric form.

IgA分两个亚型：IgA1和IgA2；IgA1主要存在于血清中，IgA2主要以二式存在于粘膜分泌液中。