TP53 and neoplasm: Cathepsin D is a lysosomal aspartate protease and overexpression of cathepsin D activates autophagy.172,173 p53 binds to two DNA sites in the cathepsin D promoter region and regulates Cathepsin D expression.174,175 The upregulation of TGM2 expression by p53 enhances autophagy, thereby inhibiting oncogenic transformation and tumor formation in primary human mammary epithelial cells.176