The effect of TGFBR2 loss in colon cancer formation was investigated in a conditional knockout Cre-Tgfbr2(flx/flx) mouse model, in which genetic ablation of the Tgfbr2 gene led to increased proliferation due to the inability to inactivate Cdk4 expression and kinase activity [81]. The gene discussed is TGFBR2; the disease is malignant colon neoplasm.