GADD45A (Growth Arrest and DNA Damage Inducible Alpha) is a stress-responsive protein that functions as a critical regulator of cellular responses to genotoxic and non-genotoxic stressors 1. The protein acts as a recognized tumor suppressor, regulating cell cycle progression, DNA repair, and apoptosis through multiple mechanisms 1. GADD45A controls cell cycle by inhibiting entry into S phase and promoting G2/M phase arrest, partly through modulating translation of cell cycle regulators like RB1 2. In cancer contexts, loss of GADD45A promotes leukemia stem cell activity and confers resistance to ferroptosis by activating antioxidant pathways including FTH1 and PRDX1 3. The protein also regulates muscle repair and metabolism by targeting ATP synthase F1 subunit alpha (ATP5A1) for ubiquitination degradation via recruitment of E3 ligase TRIM25, thereby decreasing ATP synthesis and inactivating cAMP/PKA/LKB1 signaling 4. In reproductive biology, GADD45A dysregulation contributes to diminished ovarian reserve by disrupting granulosa cell differentiation and proliferation 5. Additionally, GADD45A serves as a stress sensor in preeclampsia, activating MKK3-p38 and JNK signaling pathways in response to hypoxia and inflammatory stimuli 6.