A new genome-editing technology namely Clustered Regularly Interspaced Palindromic Repeats has been discovered in the late 1980s as part of the adaptive immune system in bacteria and archaea but yet, but many aspects of the biological tool were still unknown including its molecular structure, functions, and mechanism. This has caused underappreciation for decades.
In the 1990s, many CRISPR-associated types of research focused on microbial genetics including enterobacteria, M. tuberculosis, cyanobacteria, and S.pyogenes. Meanwhile, in the early 2000s, researchers began to explore in detail the structure and components, especially the Cas gene. By 2005, they started to understand the molecular structure of CRISPR and its mechanism of action which later drive the system to be applied in many branches of medicine including in oncology.
The Discovery of CRISPR/Cas9 technology has revolutionized the application of the gene-editing system in life sciences and medical research. Previously, researchers had employed a few other gene-editing technology systems such as zinc finger nuclease and transcription activator-like effector nuclease. In ZFN, it contains structurally zinc finger dimers that specifically recognize and bind to the target site.