Cancer is one of the most leading causes of mortality all over the world and remains a
foremost social and economic burden. Mutations in the genome of individuals are taking place
more frequently due to the excessive progress of xenobiotics and industrialization in the present
world. With the progress in the field of molecular biology, it is possible to alter the genome and to
observe the functional changes derived from genetic modulation using gene-editing technologies.
Several therapies have been applied for the treatment of malignancy which affect the normal body
cells; however, more effort is required to develop vsome latest therapeutic approaches for cancer
biology and oncology exploiting these molecular biology advances. Recently, the Clustered Regularly
Interspaced Short Palindromic Repeats (CRISPR) associated protein 9 (Cas9) system has
emerged as a powerful technology for cancer therapy because of its great accuracy and efficiency.
Genome editing technologies have demonstrated a plethora of benefits to the biological sciences.
CRISPR- Cas9, a versatile gene editing tool, has become a robust strategy for making alterations to
the genome of organisms and a potent weapon in the arsenal of tumor treatment. It has revealed an
excellent clinical potential for cancer therapy by discovering novel targets and has provided the
researchers with the perception about how tumors respond to drug therapy. Stern efforts are in
progress to enhance its efficiency of sequence specific targeting and consequently repressing offtarget
effects. CRISPR-Cas9 uses specific proteins to convalesce mutations at genetic level. In
CRISPR-Cas9 system, RNA-guided Cas9 endonuclease harnesses gene mutation, DNA deletion or
insertion, transcriptional activation or repression, multiplex targeting only by manipulating
20-nucleotide components of RNA. Originally, CRISPR-Cas9 system was used by bacteria for
their defense against different bacteriophages, and recently this system is receiving noteworthy
appreciation due to its emerging role in the treatment of genetic disorders and carcinogenesis.
CRISPR-Cas9 can be employed to promptly engineer oncolytic viruses and immune cells for
cancer therapeutic applications. More notably, it has the ability to precisely edit genes not only in
model organisms but also in human being that permits its use in therapeutic analysis. It also plays a
significant role in the development of complete genomic libraries for cancer patients. In this
review, we have highlighted the involvement of CRISPR-Cas9 system in cancer therapy accompanied
by its prospective applications in various types of malignancy and cancer biology. In addition,
some other conspicuous functions of this unique system have also been discussed beyond