Numerous Ca2+-dependent proteins containing Ca2+-binding sites, such as calmodulin (CaM) [123, 124], Ca2+/CaM-dependent kinase (CaMK) [125], calreticulin [126], Ca2+ sensor [127], Ca2+-sensing receptor (CaSR) [128], calpain [129], calcineurin [130], myosin light-chain kinase (MLCK) [131] and phospholipase S100 family proteins [132], have been widely proven to be vital to cancer metastasis. Here, CALR is linked to cancer.