CTSD and neoplasm: In terms of molecular mechanisms, ZKSCAN3 drives malignant progression through multiple pathways: (1) up-regulation of Mitogen-Activated Protein Kinase Kinase 2 (MEK2), RAS Guanyl Releasing Protein 2 (RasGRP2), Insulin-Like Growth Factor 2 (IGF-2), and ITGβ4 to promote tumor proliferation; (2) activation of the MST1R signaling axis and inducing the expression of MMP-2/9 and cathepsin D to enhance invasive metastasis; and (3) stimulation of VEGF secretion to promote tumor angiogenesis [69,70,71].