Many species of mushrooms seemingly appear overnight, growing or expanding rapidly. They are used extensively in cooking, in many cuisines (notably Chinese, Korean, European, and Japanese). People who collect mushrooms for consumption are known as mycophagists, and the act of collecting them for such is known as mushroom hunting, or simply "mushrooming". A number of species of mushrooms are poisonous. Separating edible from poisonous species requires meticulous attention to detail. Common best practice is for wild mushroom pickers to focus on collecting a small number of visually distinctive, edible mushroom species that cannot be easily confused with poisonous varieties. Some mushrooms are used or studied as possible treatments for diseases. Historically in traditional Chinese medicine, mushrooms are believed to have medicinal value, although there is no evidence for such uses.