Consistent with numerous previous reports (Nasef et al., 2007; DelaRosa et al., 2009; Najar et al., 2010; Menta et al., 2014; Kuca-Warnawin et al., 2021a,b), we confirmed that in co-cultures with activated PBMCs, the anti-proliferative action of ASCs, both obtained from HD and SLE and SSc patients, toward CD4+ and CD8+ T cells, is critically dependent on soluble factors (Figure 3). This evidence concerns the gene CD4 and systemic lupus erythematosus.