Coating with TGF-β1 augments inhibition of T-cell activation by CTCL cells or PBMCs from patients with SS. Varying cell numbers of MJ cells (A) or PBMCs (B) from Pt. 3A were treated with or without TGF-β1 and cocultured with CD4⁺ T cells isolated from healthy donors in the presence of anti–CD3 Ab. T-cell activation was assessed by ³H-thymidine incorporation or IL-2 production.