IL13 and asthma: The 5q23.2-q34 region contains the cytokine gene cluster (IL4, Il13, IL5, IL12B) and has previously been suggested as an asthma/atopy susceptibility locus [3] and the 7p21.1-14.1 region contains the previously identified asthma susceptibility gene, GPRA (7p14.3) [30].