IL20 and rheumatoid arthritis: Additionally, targeting IL-20 signaling has resulted in a promising therapeutic approach against RA, diabetic nephropathy, osteoarthritis, psoriasis, and cancer (Hsu and Chang, 2010, 2014, 2017; Wang et al., 2012; Chiu et al., 2014; Hsu et al., 2015, 2016, 2017a,b; Zhang et al., 2017).