In Cystic Fibrosis thick sticky mucus presses down on cilia inside the lungs preventing the cilia from beating and clearing the mucus. The cause of this problem is an abnormal CFTR protein created from genetic mutations inside the cell nucleus. Our goal is to replace and repair the abnormal DNA sequence to create a functional protein and restore normal mucus. One way to do this is to use gene editing technologies that cut out and replace defective parts of DNA, such as CRISPR Casts 9. The CRISPR cast 9 repair system has three components: a guide RNA that seeks out and binds to a specific location in the DNA; the cast 9 nucleus enzyme, a type of molecular scissors that cuts the genetic sequence at the precise binding site; and a repair template containing the correct genetic sequence for the gene. Once theses three components are introduced into the cell, the guide RNA binds to and activates the cast 9 nucleus. Now the cast 9 nucleus, the molecular scissors can search the cell’s DNA for potential targets. At a potential target site, cast 9 unwinds a section of DNA to see of the guide RNA sequence matches. If the DNA sequence matches the guide RNA, the cast 9 nucleus cuts the DNA to create a break in the strands. To replace the mutation with a normal sequence a repair process has use, that precisely edits the DNA. For this editing process to work, a short piece of DNA template that contains the desired normal gene sequence is introduced into the cell. The cell uses this fragment as a template and copies, the new sequence as it repairs the broken DNA. Once the first strand has been repaired, the template falls away, and the other strand of DNA uses the repaired strand to fill in the remaining gap, leaving both strains with the corrected gene sequence. The cell then uses the corrected DNA strand to produce a functional CFTR protein that allows the proper flow of salt and fluids through the cell membrane. Mucus returns to normal within the lung, allowing the cilia to beat freely and clear lungs from germs and irritants, as well as absorb the oxygen for resperatiion.