GATA3 and Cowden syndrome 1: Although we observed IL-4 production by TOX+ CD4+ T cells from CTCL plaques, GATA-3 did not show differences in expression level between the CTCL and CS specimens and showed significantly lower expression in CTCL relative to AD (Supplementary Figure 2, 3 and 6D), suggesting that GATA-3 was not totally responsible for the basal IL-4 expression observed in CTCL CD4+ T cells and indicating the occurrence of alternative regulation mechanisms for IL-4 expression.