Cyclin D dysregulation is a common feature in many types of cancer. Overexpression or amplification of Cyclin D genes (e.g., CCND1) can lead to excessive cell proliferation. In cancers such as breast cancer and mantle cell lymphoma, Cyclin D1 is often overexpressed. Targeting Cyclin D/CDK4/6 complexes has become a therapeutic strategy, with several CDK inhibitors being developed and used in clinical settings.
