Abstract: Clustered regularly interspaced short palindromic repeats-associated proteins 9 (CRISPR/Cas9) technology can be used to knock-in,  replacement or knock-out of eukaryotic genes. Injecting the RNP Cas9 (VEGFA gene-specific Cas9 ribonucleoproteins) under the mouse retina can significantly reduce the area of laser-induced choroidal neovascularization (CNV). Targeting small molecule protein CjCas9 to knock out VEGFA(vascular endothelial growth factor A)or HIF-1(hypoxia-inducible factor 1)genes of RPE(retinal pigment epithelium) can also effectively reduce the area of laser-induced CNV,  and its mutation can maintain exceed 1 year. At the retinal level,  knocking out VEGFA in RPE cells or VEGFR2 in human microvascular endothelial cells (HRECs) by CRISPR/Cas9 technology can significantly inhibit the formation of retinal neovascularization. After knocking down the small ubiquit in-like modifier-specific protease 1 (SUMO-specific protease 1,  SENP1) induced by endothelial cells,  the SUMO-turned VEGFR2 in the Golgi can also effectively inhibit pathological neovascularization. After knocking out the p110δ in HRECs,  the proliferation,  migration and tube formation ability of HRECs were all weakened. The drug idelalisib,  which targets PI3Kδ,  can also inhibit pathological retinal neovascularization. Using CRISPR/Cas9 technology to knock out SCP1 (aspartic proteinase 1) can change the phosphorylation state of AKT and affect the formation of new blood vessels. The CRISPR/Cas9 synergistic activation mediator (SAM) system can screen out the positive regulator AK023948 of AKT. Knock down of AK023948 can inhibit the activity of AKT,  thereby inhibiting the formation of new blood vessels. (Int Rev Ophthalmol,  2020,  44:  408-413)

Key words: clustered regularly interspaced short palindromic repeats-associated proteins 9 (CRISPR/Cas9), neovascularization, PI3K/AKT pathway