YES1P1 and influenza: As SYR increased the frequencies of total CD3+ T cells and naïve T cells in both CD4+ and CD8+ T-cell populations (Fig. 1) and their functions in vitro upon TCR stimulation (Fig. 2), we further examined whether SYR50 could enhance humoral immune responses to influenza vaccine in vivo by measuring anti-influenza HA antibody titers following influenza vaccination.