Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas genome editing has advanced from an experimental tool to a clinically validated therapeutic platform in hematology. Landmark successes in inherited blood diseases including sickle cell disease, β-thalassemia, and severe combined immunodeficiency, have demonstrated that precise and durable genetic modifications can be safely and effectively implemented in human hematopoietic cells, positioning hematology at the forefront of translational genome editing. Beyond monogenic disease, CRISPR-based approaches are transforming both the biological understanding and treatment of hematologic malignancies by enabling systematic interrogation of cancer dependencies, functional mapping of genetic vulnerabilities, and mechanism-driven target validation, including in vivo and immune-relevant contexts. In parallel, therapeutic applications are emerging through the development of engineered cellular therapies, including edited autologous and allogeneic immune effector cells designed to enhance antitumor efficacy, persistence, and immune evasion. This review synthesizes recent CRISPR-based advances across benign and malignant hematologic diseases. We compare major editing modalities, including nuclease-mediated disruption, base editing, prime editing, and CRISPR-based transcriptional modulation, and highlight key preclinical studies alongside emerging clinical trial data. We also discuss translational challenges that currently limit broader clinical adoption, including delivery and manufacturing scalability, off-target and genotoxicity risks, tumor and immune heterogeneity, and the long-term durability and fitness of edited cell populations. Finally, we outline priorities for the next phase of the field, emphasizing how continued innovation in CRISPR technologies may enable increasingly precise, durable, and mechanism-informed therapeutic strategies in hematology.
