CFH and neoplasm: However, to increase the specificity, high-fidelity Cas9 variants, such as eSpCas9 and SpCas9-HF1, and base-editing technologies have been developed, and research is still needed to ensure long-term genomic stability and avoid deleterious mutations.[26–30] Delivery efficiency and tumor targeting: The effectiveness of CRISPR/Cas9 depends on effective delivery.