Prion proteins are misfolded proteins that can cause normal proteins in the brain to also misfold, leading to serious neurological diseases. These diseases, known as prion diseases, include conditions like Creutzfeldt-Jakob disease and mad cow disease. Prions are unique because they can induce changes in other proteins without any genetic material, making them different from typical infectious agents like bacteria or viruses. Prion diseases are often progressive and fatal, affecting brain function and leading to symptoms such as memory loss, personality changes, and coordination problems. They are transmissible, meaning they can spread between individuals, often through contaminated food or medical procedures. Understanding prion proteins is crucial for developing treatments and preventive measures against these diseases.