IL13 and systemic sclerosis: In SSc, cytokines such as IL-4, IL-6, IL-10, IL-13 and transforming growth factor-ß (TGF-ß) have been reported to play important pathogenic roles (Ludwicka et al. 1992; Needlemann et al. 1992; Patrick et al. 1995), and the serum levels of these cytokines have been shown to be higher in patients with SSc than in healthy volunteers (Needlemann et al. 1992; Hasegawa et al. 1997; Hasegawa 1998).