User:Zachary K. Martin/sandbox

Cas9 uses cell-specific promoters allowing the a controlled use of the Cas9. Cas9 is an accurate method of treating diseases due to the targeting of the Cas9 enzyme only affecting certain cell types. The cells undergoing the Cas9 therapy can also be removed and reintroduced to provide amplified effects of the therapy.

Cas9 has been used often as a genome-editing tool. Cas9 has been used in recent developments in preventing viruses from manipulating hosts’ DNA. Since the CRISPR-Cas9 was developed from bacterial genome systems, it can be used to target the genetic material in viruses. The use of the enzyme Cas9 can be a solution to many viral infections. Cas9 possesses the ability to target specific viruses by the targeting of specific strands of the viral genetic information. More specifically the Cas9 enzyme targets certain sections of the viral genome that prevents the virus from carrying out its normal function. Cas9 has also been used to disrupt the detrimental strand of DNA and RNA that cause diseases and mutated strands of DNA. Cas9 has already showed promise in disrupting the effects of HIV-1. Cas9 has been shown to suppress the expression of the long terminal repeats in HIV-1. When introduced into the HIV-1 genome Cas9 has shown the ability to mutate strands of HIV-1. Cas9 has also been used in the treatment of hepatitis b through targeting of the ends of certain of long terminal repeats in the hepatitis b viral genome. In addition, Cas9 has already been used in human trials in the treatment of cystic fibrosis and oncogenic mutations in human pluripotent stem cells. Cas9 has used to repair the mutations causing cataracts in mice.

Cas9 has had controversial backlash. Cas9 therapy involves the reworking the functions of the cells. It has been hypothesized that the Cas9 enzyme will disrupt or alter the functions of neighboring cells. Cas9 has also been shown to target viruses that are outside the specified parameters due to certain similarities in the viruses. Cas9 can tolerate a number of mismatches in the genomic sequence; allowing the Cas9 enzyme to split parts if the genomic sequence that falls outside the target sequence. In addition, Cas9 is feared to change the genetic makeup of future generations if it is allowed to be used in humans for the therapy. Many people have skepticism towards the Cas9 therapy in the humans due to the fear of unknown arbitrary effects in the human genome in future generations.