Deficiencies in Tfr cells have been shown to promote humoral autoimmunity in mouse models and aberrant Tfh/Tfr ratios are found in several autoimmune conditions (10, 11), including the pancreatic lymph nodes (pLN) of organ donors with T1D (12), suggesting that enhancing Tfr cell function could contribute to disease remission and blunt undesired antibody responses. Here, TFRC is linked to type 1 diabetes mellitus.