Inflammation in allergic asthma is mediated by T-helper type 2 (Th2) cytokines. The expression of these cytokines is dependent on specific and nonspecific transcription factors that bind to regulatory sequences in the promoter. GATA-3 is a Th2-specific transcription factor that belongs to the zinc finger family and binds to the interleukin (IL)-5 promoter. It has also binding sites around the IL-4/IL-13 locus. Another Th2 specific transcription factor is c-maf, which transactivates the IL-4 promoter but does not appear to regulate the expression of other Th2 cytokine genes.