TGFB1 and myeloproliferative neoplasm: Serum TGF-β1 levels were elevated in MPN patients (Supplementary Fig. 3a), and showed a weak negative correlation with JAK2-V617F allele burden (Supplementary Fig. 3a), but no correlation between TGF-β1 and IL-1β serum levels was found (Supplementary Fig. 3b).