Genes that are associated with complex diseases, like asthma interleukin‐13 (Fullerton et al., 2002), IL‐4 (Rockman, Hahn, Soranzo, Goldstein, & Wray, 2003; Sakagami et al., 2004) and IL‐1A (Akey et al., 2004), [cytochrome P450 (CYP3A) (Thompson et al., 2004), cardiovascular disease [matrix metallopeptidase 3(MMP3) (Rockman et al., 2003), and (AGT) (Nakajima et al., 2004) type 2 diabetes (CAPN10 (Fullerton et al., 2002)] have also reported as positive signature selection in different studies. The gene discussed is IL4; the disease is asthma.