In both types of synoviocytes, the accumulation of Zn was increased by the combination of IL-17 and TNF-α in comparison to the control situation (Fig 1C, OA synoviocytes: 0.11 ± 0.01 ng/106 cells without cytokines vs. 0.17 ± 0.02 ng/106 cells with cytokines, p = 0.04; RA synoviocytes: 0.09 ± 0.01 ng/106 cells without cytokines vs. 0.14 ± 0.02 ng/106 cells with cytokines, p = 0.02; S1 Table). Here, IL17A is linked to rheumatoid arthritis.