The calpains, calcium-activated neutral proteases, are nonlysosomal, intracellular cysteine proteases. The mammalian calpains include ubiquitous, stomach-specific, and muscle-specific proteins. The ubiquitous enzymes consist of heterodimers with distinct large, catalytic subunits associated with a common small, regulatory subunit. This gene encodes the large subunit of the ubiquitous enzyme, calpain 1. Several transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Nov 2010],CANP, CANP1, CANPL1, SPG76, muCANP, muCL,Apoptosis,Calcium Signaling,Cell Biology & Developmental Biology,Immunology & Inflammation,Neurodegenerative Diseases,Neurodegenerative Diseases_Amyloid Plaque and Neurofibrillary Tangle Formation in Alzheimers Disease,Neuroscience,Signal Transduction,T Cell Receptor Signaling Pathway,Ubiquitin,CAPN1