In the landscape of childhood cancer, there are diseases so rare that even many physicians will never encounter a single case. Yet within these rare diagnoses lie some of the deepest biological insights and some of the most urgent clinical challenges. Choroid plexus carcinoma, often abbreviated as CPC, is one such disease. It is a malignant brain tumor that arises predominantly in very young children, most often under the age of four. Though rare, it is biologically revealing, clinically formidable, and, in recent years, the focus of a determined effort to change its outcome.

On a warm spring afternoon in the northeastern United States, a walk through tall grass can feel harmless, even restorative. Yet hidden in the undergrowth is a growing public health concern that few people recognize by name. The Powassan virus is rare, but it is dangerous, and its quiet rise is reshaping how scientists think about tick borne disease, climate change, and neurological illness. In a recent review published in the journal Virulence, researchers Manpreet Kaur, Monica Adam, and Prof. Megan Mladinich Valenti bring together decades of scattered research to tell the evolving story of this virus and the risks it poses.