TNF and varicose ulcer: Notably, the concentration ranges of TNF-α (0 to 2 ng ml−1), TGF-β1 (0 to 150 pg ml−1), IL-8 (0 to 30 ng ml−1), and IL-6 (0 to 30 ng ml−1) were based on levels reported in wound fluids from patients with venous ulcer (16, 17, 19, 45), combined with ELISA results from clinical samples used for this study.