CD4 and progeroid syndrome: In this unique study, we identified that immune cells, especially CD4+ T and CD8+ T cells, have a progeria-like pattern (limited naïve T cells and expanded TCR clonotypes) (Sun 2022; Young et al. 2023), which recapitulates the previously described clinical phenotype of MSS patients (NORD 2024; Passarelli, et al. 2018).