FAS and systemic lupus erythematosus: Furthermore, the associations between soluble forms of Fas and FasL in systemic lupus erythematosus, autoimmune disease, and tumor have been widely reported in the past years (Perianayagam et al., 2000; Sahinarslan et al., 2012; Iso et al., 2017; Chiloff et al., 2020).