TNF and scleroderma: In addition to our observations, Reber et al. reported that RelA is phosphorylated at Ser276 and Ser536 in IL-1β-stimulated lung fibroblasts.31 We could also induce RelA-P-Ser536 by TNF-α in healthy human skin fibroblasts and observe this modification in dermal fibroblasts in patients with scleroderma (Fig. 6D-F).