Abstract
CRISPR-based transcriptional regulation technologies, including CRISPR activation (CRISPRa) and CRISPR interference (CRISPRi), offer precise and programmable control over gene expression, representing a major advance in gene and epigenetic therapy. CRISPRa uses nuclease-inactive Cas proteins fused to transcriptional activators to upregulate target genes, while CRISPRi employs repressor domains for gene silencing. Preclinical studies have demonstrated the efficacy of CRISPRa/i in models of metabolic, neurological, muscular, and oncological diseases. Notably, CRISPRi-based therapies have entered clinical trials for conditions like hepatitis B and muscular dystrophy, showing encouraging safety and efficacy profiles. Despite ongoing challenges related to delivery efficiency, immunogenicity, and off-target activity, innovations in protein engineering and guide RNA design are rapidly enhancing the precision and safety of these technologies. Overall, CRISPRa and CRISPRi are poised to transform the treatment of genetic and epigenetic disorders, with continued optimization expected to accelerate their clinical adoption and broaden their therapeutic impact.