Calbindin D28k is a member of a large family of intracellular calcium-binding proteins, containing EF-hand calcium binding motifs, and related to calmodulin and troponin-C. The biological roles of Calbindin D28k include calcium regulation and calcium-dependent signalling in neurons and during development. Decreases in Calbindin D28k abundance, or loss of Calbindin D28k immunoreactivity, is found in models of neurological disorders such as epilepsy, and in neurodegenerative diseases. Calbindin antibody is often used as a marker for cerebellum Purkinje cells.