In contrast to IFNγ, IL-4 has been shown to stimulate dermal fibroblasts from CTCL patients to express high levels of the Th2-recruiting chemokine CCL26 in vitro and, accordingly, the expression levels of IL-4 and CCL26 were found to correlate in the lesional skin (Miyagaki et al., 2010). Here, IL4 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.