Why fetal cells continue to divide but terminally differentiated adult cells do not divide -
A cyclin-dependent kinase inhibitor protein is a protein which inhibits cyclin-dependent kinase. Several function as tumor suppressor genes. Cell cycle progression is negatively controlled by cyclin-dependent kinases inhibitors (called CDIs, CKIs or CDKIs). CDIs are involved in cell cycle arrest at the G1 phase.
There are many cyclin inhibitors which prevent cell to enter into S phase in adult
Phosphatase absent in fetal cells
Proteinase is absent in fetus
Absence of CD kinase
General pathology