Cell Division Cycle

Growth Signal: 1.0

DNA Damage: 0.0

CDK4 Activity: 1.0

CDK2 Activity: 1.0

Checkpoints

G1/S checkpoint: PASS

G2/M checkpoint: PASS

Spindle checkpoint: PASS

Cell Cycle Phases
G1 = growth
S = DNA synthesis
G2 = preparation for division
M = mitosis

p53 activates under DNA damage → p21 inhibits CDKs → cell arrest.