In molecular biology to understand the critical role/s played by certain gene products, the encoding genes are often disrupted, and the effects are further analyzed to ascertain the exact function of the gene/protein in the development of the organisms. Recently emerged gene editing technique revolutionized the field of biology to study the pathology of various diseases and in the discovery of drugs. Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (CRISPR-Cas9) attracted the attention of the World due to its impeccable potential in research and therapeutic applications. Unlike other techniques, CRISPR can deactivate a gene without interfering with intracellular mechanisms. It can be used to understand the genetic and epigenetic aspects of various diseases especially cancer. CRISPR can be used to induce specific mutations in oncogenes and tumor suppressor genes in cell lines to model the cancers to understand the pathology and to develop effective drugs. CRISPR-Cas9 holds the promising potential to treat genetic diseases such as Duchenne muscular dystrophy, Hemophilia, β-Thalassemia, and cystic fibrosis. However, there are some challenges and concerns which needs to addressed. In this review, we discuss on the origin of CRISPR-Cas9 technology, how it works, genome/nongenome editing for targeted molecular therapy and future directions. © 2019 Mattingley Publishing. All rights reserved.