{Reference Type}: Journal Article {Title}: The Current Situation and Development Prospect of Whole-Genome Screening. {Author}: Yang C;Lei Y;Ren T;Yao M; {Journal}: Int J Mol Sci {Volume}: 25 {Issue}: 1 {Year}: 2024 Jan 4 {Factor}: 6.208 {DOI}: 10.3390/ijms25010658 {Abstract}: High-throughput genetic screening is useful for discovering critical genes or gene sequences that trigger specific cell functions and/or phenotypes. Loss-of-function genetic screening is mainly achieved through RNA interference (RNAi), CRISPR knock-out (CRISPRko), and CRISPR interference (CRISPRi) technologies. Gain-of-function genetic screening mainly depends on the overexpression of a cDNA library and CRISPR activation (CRISPRa). Base editing can perform both gain- and loss-of-function genetic screening. This review discusses genetic screening techniques based on Cas9 nuclease, including Cas9-mediated genome knock-out and dCas9-based gene activation and interference. We compare these methods with previous genetic screening techniques based on RNAi and cDNA library overexpression and propose future prospects and applications for CRISPR screening.