English: Image shows how 4 isoforms can be produced as a result of 2 different haplotypes. DQ genes are expressed within the nucleus, the resulting RNA are transported out of the nucleus and independently translated into polypeptides and transported across the endoplasmic reticulum where alpha and beta chains are process and fold into their final form, a DQ heterodimer. While some alpha may prefer to pair with certain beta, in many instances they can pair to an isoform encoded by the other 'parents' haplotype resulting in a trans-isoform. When the isoforms are encoded by the same haplotype, the form a cis-haplotype isoform.