Xufei Zhou, Rucheng Diao, Xin Li, Christine A. Ziegler, Max J. Gramelspacher, Lydia Freddolino, Zhonggang Hou, Yan Zhang. "Cas9 senses CRISPR RNA abundance to regulate CRISPR spacer acquisition." Nature, 2025. doi:10.1038/s41586-025-09577-9