The article introduces NanoCas, a miniaturized version of the CRISPR-Cas9 gene editing tool developed by Mammoth Biosciences. NanoCas reduces the size of the Cas9 component to about one-third of its original size, enabling it to be delivered more effectively to various tissues in the body. This advancement addresses the delivery challenges of traditional CRISPR systems, which are often too large for efficient in vivo applications. NanoCas has shown promising results in editing genes related to inherited high cholesterol and Duchenne muscular dystrophy in mice and monkeys, potentially expanding the scope of gene therapies beyond liver-targeted and ex vivo treatments.