Some classic pathways described for KLF6 tumor suppressor activity include activation of the cyclin-dependent kinase inhibitor p21 through a p53-independent mechanism, reduction of the cyclin D1/CDK4 complex via direct interaction with cyclin D1 leading to cell cycle arrest, inhibition of the proto-oncoprotein c-Jun activities, downregulation of VEGF expression, which impacts angiogenesis, upregulation of E-cadherin associated with maintaining cell adhesion and inhibiting metastasis, and induction of apoptosis in cancer cells [124]. The gene discussed is CDK4; the disease is cancer.