Hajizadeh Dastjerdi, ArashNewman, AnthonyBurgio, Gaetan2021-07-082021-07-08Hajizadeh Dastjerdi, A., Newman, A. & Burgio, G. The Expanding Class 2 CRISPR Toolbox: Diversity, Applicability, and Targeting Drawbacks. BioDrugs 33, 503–513 (2019). https://doi.org/10.1007/s40259-019-00369-y1173-8804http://hdl.handle.net/1885/238631The class 2 clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system, one of the prokaryotic adaptive immune systems, has sparked a lot of attention for its use as a gene editing tool. Currently, type II, V, and VI effector modules of this class have been characterized and extensively tested for nucleic acid editing, imaging, and disease diagnostics. Due to the unique composition of their nuclease catalytic center, the effector modules substantially vary in their function and possible biotechnology applications. In this review, we discuss the structural and functional diversity in class 2 CRISPR effectors, and debate their suitability for nucleic acid targeting and their shortcomings as gene editing tools.Dr. Burgio’s research program is supported by the National Health and Medical Research Council of Australia (APP1143008), the Australian Research Council (DP180101494), and the National Collaborative Research Infrastructure Strategy (NCRIS) via the Australian Phenomics Network. Arash Hajizadeh Dastjerdi is supported by a JCSMR postgraduate scholarship, and Anthony Newman is supported by a Research Training Program domestic scholarship.© 2019 Springer Nature Switzerland AG2019-08-0510.1007/s40259-019-00369-y