The serum TARC level and sIL-2R level did not show any significant correlation with the MFI of GD3 in the malignant T cells or the IL-17A production from the benign CD4 T cells (Supplementary Figure S2A), although these indexes are known to indicate the disease activity in CTCL (20, 21). Here, IL17A is linked to primary cutaneous T-cell non-Hodgkin lymphoma.