WNT5A and rheumatoid arthritis: As shown in Figure 1, regulation of the Wnt signalingpathwayin rheumatoid arthritis involves interleukin-1 beta,tumor necrosis factor alpha, and interleukin-6, which activatethe expression of the WNT5A gene encoding the WNT5Aprotein – a ligand of FZD receptors participating in the noncanonicalWnt pathway (Miao et al., 2013).