PELI1 and viral infectious disease: Accumulating evidence has established the critical role of Tfh cells in initiating humoral immune responses and antibody production,26–28 which promote lupus-like autoimmunity but protect against viral infection.4,5,23,29 A previous study suggested that the microRNA miR-155 is critical for Tfh cell differentiation by potentially targeting Peli1,11 a T-cell-enriched E3 ubiquitin ligase.10 However, whether Peli1 can intrinsically modulate Tfh cell differentiation and Tfh-related physiological functions remains elusive.