T time for ADAR : ADAR 1 is required for T cell self‐tolerance

ADAR 1, an RNA ‐editing enzyme, plays a key role in preventing self‐ RNA s from triggering autoinflammatory responses. In this issue of EMBO reports , Nakahama and colleagues uncover a novel role for ADAR 1 in T cells [1][Nakahama T, 2018]. The authors report that in T cells, ADAR 1‐mediated suppression of type I interferon‐stimulated gene ( ISG ) expression is required for thymic T cell self‐tolerance and prevention of colitis. These findings establish a novel function of ADAR 1 in T cells and suggest that autoreactive T cells may contribute to disease symptoms in autoinflammatory disorders.