Three clinical trials using agonistic anti-BTLA antibodies (LY3361237, Stanford University and Eli Lilly and Company and ANB032 from AnaptysBio) are currently undergoing in patients with systemic lupus erythematosus (NCT05123586), Sjogren's syndrome (NCT05781451), and severe atopic dermatitis (NCT05935085). Here, BTLA is linked to systemic lupus erythematosus.