A point of interest, or POI, is a specific point location that someone may find useful or interesting. An example is a point on the Earth representing the location of the Space Needle, or a point on Mars representing the location of the mountain, Olympus Mons. Most consumers use the term when referring to hotels, campsites, fuel stations or any other categories used in modern (automotive) navigation systems. In medical fields such as histology/pathology/histopathology, points of interest are selected from the general background in a field of view; for example, among hundreds of normal cells, the pathologist may find 3 or 4 neoplastic cells that stand out from the others upon staining.