Ribociclib is a medication used to treat certain types of breast cancer, specifically hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+ HER2-) breast cancer. It works by inhibiting specific proteins called cyclin-dependent kinases (CDK4 and CDK6), which are involved in cell division. By blocking these proteins, ribociclib helps slow down the growth of cancer cells. Typically, ribociclib is prescribed in combination with other treatments, such as aromatase inhibitors, to enhance its effectiveness. It is taken orally in pill form and is usually part of a broader treatment plan managed by an oncologist. Regular monitoring is essential to manage potential side effects.