What Happens When the Restriction Point is Defective?
Defects in the restriction point mechanisms can lead to cancer. For instance, mutations in the gene encoding the Rb protein can prevent it from properly inhibiting E2F transcription factors, resulting in unchecked progression to the S phase. Similarly, overexpression of cyclins or loss of CKIs can lead to hyperactivation of CDKs, further contributing to unregulated cell proliferation.
