CRISPR, and specifically Cas9 from S. Pyogenes (SpCas9), is truly an exceptional genome engineering tool. It is easy to use, functional in most species, and has many application (see a review of CRISPR applications here). That said, SpCas9 is not the only game in town, and several non-SpCas9 molecules have been characterized. Early research suggests that these molecules may circumvent the limitations associated with SpCas9 (see our blog entitled “Which Cas9 do I choose for my experiment”). A novel protein, Cas13a (previously referred to as C2c2), has several unique properties that make it particularly useful and further expand the CRISPR toolbox. This blog post will cover how Cas13a was identified, the structure and function of Cas13a with a focus on what makes this molecule unique, and the various applications of Cas13a.