Neapolitan pizza is a style of pizza made with tomatoes and mozzarella cheese. By tradition it must be made with either San Marzano tomatoes or Roma tomatoes. It is a Traditional Speciality Guaranteed (TSG) product in Europe, and the art of its making is included on UNESCO's list of intangible cultural heritage. This style pizza gave rise to the New York-style pizza that was first made by Italian immigrants to the United States in the early 20th century. A genuine Neapolitan pizza dough consists of wheat flour (type 0 or 00, or a mixture of both), natural Neapolitan yeast or brewer's yeast, salt and water.