Site-directed mutagenesis refers to the scientific technique of deliberately modifying a specific nucleotide sequence in a targeted gene to introduce specific changes in its protein products. Some synonyms for site-directed mutagenesis include targeted gene editing, site-specific mutagenesis, gene manipulation, and genetic engineering. These techniques have been used to generate transgenic organisms, develop new vaccines, reprogram cells, and produce enzymes with improved functions. With the advancement of gene-editing technologies, site-directed mutagenesis has become an increasingly important tool for genetic research, opening up new avenues for disease treatment, crop improvement, and biotechnological innovations.