In 2024, ~10 million cancer deaths were reported worldwide, with 21 million newly diagnosed cancer patients. Metastasis—the spread of cancer to other organs usually via the blood or lymph—remains the primary cause of cancer-related deaths, often occurring after initial treatments like chemotherapy, radiation, or surgery have failed to eliminate every cancer cell. Once standard therapies have failed and cancer has metastasized, the management of the disease shifts significantly.

According to the World Health Organization, more than 3 billion people lived with a neurological condition worldwide in 2021, and there are currently more than 55 million people living with dementia. Alzheimer's disease is the 6th leading cause of death in the U.S., and nearly 1 million Americans live with Parkinson's disease.