In the cell cycle, G0 represents a restriction checkpoint. Which of the following is NOT true about G0?
Cells can reenter the growth cycle being in G0 if needed (injury, mutation, etc.).
Some cells remain in G0 permanently.
Few, if any, adult cells are usually at this rest phase.
Many different cell types that are at rest in G0 are resistant to conventional chemotherapy regimes.
Many adult cells spend most time in G0 unless absolutely needed.