IKZF2 and systemic lupus erythematosus: Therefore, it seems likely that such thymic-derived, naturally occurring ICOS+ or ICOS−-Tregs may be expanded in active SLE in order to compensate for autoreactive effector responses, which were shown for FoxP3+Helios+ Tregs and more recently for a special CD25low+FoxP3+ Helios+-Treg subset [46,47,48].