It is found to suppress proliferation, migration, and invasion of BC cells by altering the expressions of several genes, including downregulation of epithelial–mesenchymal transition (EMT), N-cadherin, Akt, snail, slug, cathepsin B, cathepsin D, MMP-2, and MMP-9 and upregulation of p-21 and E-cadherin. Here, CTSD is linked to breast cancer.