Calcium-regulated non-lysosomal thiol-protease which catalyzes limited proteolysis of substrates involved in cytoskeletal remodeling and signal transduction (PubMed:19617626, PubMed:21531719, PubMed:2400579). Proteolytically cleaves CTBP1 at 'Asn-375', 'Gly-387' and 'His-409' (PubMed:23707407). Cleaves and activates caspase-7 (CASP7) (PubMed:19617626). {ECO:0000269|PubMed:19617626, ECO:0000269|PubMed:21531719, ECO:0000269|PubMed:23707407, ECO:0000269|PubMed:2400579}. This is the function of Ensembl gene identifier ENSG00000014216 (CAPN1, calpain 1).