TCR Vβ repertoire of patients with MAS/sHLH does not show expansion of a particular TCR Vβ in CD3⁺ T cells compared with patients with active sJIA. The TCR Vβ repertoire was evaluated in peripheral CD3⁺ cells of patients enrolled in the replication cohort (16 patients with MAS/sHLH and 9 patients with active sJIA). Statistical significance was calculated using the Mann-Whitney test. *P < .05.