CAST and metastatic malignant neoplasm in the lymph nodes: Significant association has been observed between tumour metastasis (i.e. vessel invasion, presence of lymph node metastasis and/or advanced tumour-node-metastasis stage) and the expression of conventional calpain subunits or calpastatin (Yang et al. 2017; Salehin et al. 2011; Storr et al. 2011b); however, it is context dependent on whether the association was positive or negative.