Potential genetic factors involved in the T-helper cell type 2 (Th2) bias in atopy
| Candidate location or gene(s) | Examples |
| Th2 regulatory regions that affect DNA binding of transcriptional or chromatin-based regulators | IL-4 and IL-13 promoters, LCR (?) |
| Th2 cytokine coding regions that affect cytokine activity | IL-13 |
| Th2-promoting signaling molecules or transcription factors | Stat6, GATA3, many other potential candidates |
| Polymorphisms that inhibit the expression/function of genes that activate Th1 cytokine gene expression | IL-12Rβ2, T-bet (?) |
| Genes that regulate Th2 cell growth or survival | GIF-1 (?) |
| Genes that induce the differentiation of Th2-promoting DC | TLR2, GPCRs (?) |
See table 1⇑ for interleukin (IL)-4 and IL-13 promoter polymorphism references. References for the following SNPs are as follows: IL-13 coding region 96, signal transducer and activator of transcription (Stat)6 97, GATA3 98, IL-12Rβ2 99, TLR2 100. Question marks indicate that no association has been shown to-date for atopic or asthmatic phenotypes. DC: dendritic cell; LCR: locus control region; GIF-1: growth-factor independent-1; TLR: toll-like receptor; GPCR: G-protein coupled receptor.