TRPA1 and osteoarthritis: Similarly, in experimental osteoarthritis, IL-6 was highly expressed in the chondrocytes of wide-type (WT) mice, whereas the expression of IL-6 was significantly downregulated in TRPA1-knockout (KO) mice.This event can be attributed to the expression of different genes toll-like receptor 2 (TLR-2), cluster of differentiation 36 (CD36), and as well as the cytokines IL-33, activation of TLR2 increases IL-6 production in the synovium (Papathanasiou et al., 2011); CD36 regulate IL-6 from dendritic cells (Lim et al., 2014); IL-33 is associated with mast cell IL-6 (Kondo et al., 2021).