TLR1 and systemic sclerosis: The level of IL-6 was also analyzed with in-house-developed bead sets in supernatants of CD56+ cells (NK/NKT-like cells) isolated from PBMCs fraction of healthy controls (mean age 47.8 ± 8.4) and SSc (systemic sclerosis) patients (mean age 56.2 ± 11.3) after stimulation with TLR1/2 (Toll-like receptor) agonists and additionally with IL-2 and IFN-α.