Enigmatic inflammasomes - Sequel (Part 2).

In this issue, we introduce the second part of our review series focusing on lesser-known enigmatic inflammasomes. This part of the collection introduces one more under-studied NLR, NLRP7, and not only its role as a regulator of inflammation in response to bacterial infections but also its non-inflammasome role in early pregnancy. In addition, the enigmatic function of extracellular ASC specks is also introduced, where extracellular ASC specks are presented as 'danger signals' to propagate inflammation. The series is concluded with an article that reviews the immunometabolic regulation of all of these lesser-known NLRs, demonstrating that metabolic regulation of inflammasome activation is central for the whole NLR family. These three reviews, together with the four articles that were published in the first part of the series in December 2020, offer new insights into the complex functions of NLRs, well beyond the well-known NLRP3. The review series as a whole provides a thought-provoking platform with some of the latest findings in the NLR field and sparks our imagination into what might be discovered in this space in the future.