By comparing female and male SLE remission patients, no age-dependent or age-independent differences could be detected for ICOS+ Tregs and the ratio of ICOS+ Tregs/Tresps, as well as for ICOS− Tregs, ICOS− Tresps and the ratio of ICOS− Tregs/Tresps. Here, ICOS is linked to systemic lupus erythematosus.