This family is found to be a divergent form of the NYN-domain- containing RNAse family.

1: Zc3h12a is an RNase essential for controlling immune responses by regulating mRNA decay. Matsushita K, Takeuchi O, Standley DM, Kumagai Y, Kawagoe T, Miyake T, Satoh T, Kato H, Tsujimura T, Nakamura H, Akira S; Nature;458:1185-1190. PMID:19322177

2: The NYN Domains: Novel Predicted RNAses with a PIN Domain-Like Fold. Anantharaman V, Aravind L; RNA Biol. 2006; [Epub ahead of print] PMID:17114934