TNF and polyarteritis nodosa: Early studies have shown that the level of IL-6 in blood (cutaneous) PAN is correlated with disease activity, making the IL-6 signaling pathway a potential target in the clinical management of PNA.[18,19] In addition, there were cases reported that patients who did not respond to IL-6 treatment received good efficacy with tofacitinib.[20] Tumor necrosis factor inhibitors are reported to be effective in pediatric PAN and adult (cutaneous) PAN patients.[21,22]