While the current paper was written, however, several studies using Malt1FL/PDFoxp3-CreTg/+ mice that specifically express catalytically inactive MALT1 in Tregs indicated that post-development loss of MALT1 proteolytic activity in Tregs leads to severe autoimmune disease (77–79), which might raise concerns regarding the safety of pharmacological inhibition of MALT1 protease activity. Here, MALT1 is linked to autoimmune disease.