Structure of the human NUP62 and IL4I1 genes at chromosomal band 19q13.33. Genes are both shown from 5' (left) to 3' (right). Exons are represented by vertical bars and boxes, intronic sequence by horizontal lines. The NUP62 gene (three exons) is located upstream and tail-to-head to the previously reported IL4I1 gene (eight exons). NUP62 has two splice variants represented by cDNAs IMAGE:3050260 (includes exon 2), and DKFZp547L134 (skipped exon 2). The Nup62 protein is encoded by exon 3 (blue box). IL4I1 does not have reported splice variants and is represented by the sequence AF293462. Translation start of the protein is located in exon 2 (blue bars represent coding region). Several cDNAs were identified to link NUP62 and IL4I1 transcripts (representative: IMAGE:5742307). The splice form consists of the first two apparent exons of the NUP62 gene, two joining exons mapping in between the reported NUP62 and IL4I1 gene loci (red arrow heads), and exons 3–8 of the known IL4I1 gene. Translation start of the protein is in the second joining exon. The sequences of the joining exons are conserved in eutherian species, but not for instance in chicken or fish (taken from UCSC genome browser ). The reported promoter of the NUP62 gene contains a CpG island, while the promoter of previously known IL4I1 does not. The two genes cover 40 kb on the chromosome.