CD44 and systemic lupus erythematosus: Among the different CD8+ Treg cell subsets defined (51, 52), we focused on CD8+ Tregs expressing the triad of the CD44, CD122, and Ly49 surface markers (in addition to Helios) due to their presence in steady-state naïve animals and their reported implications in the lupus-like phenotypes (12, 15), as well as in other autoimmune models (17, 53), and their very recent description in human autoimmunity as KIR+ CD8+ T cells (9).