– Growth Arrest and DNA Damage-Inducible Protein GADD45 Υ (GADD45G) is a nuclear protein which belongs to the GADD45 family. GADD45G is highly expressed in placenta. GADD45G interacts with various proteins whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents. GADD45G responds to environmental stresses by mediating activation of the p38/JNK pathway via MTK1/MEKK4 kinase. GADD45G is also involved in the regulation of growth and apoptosis. GADD45G inhibits cell growth and differentiation by androgens. The mRNA expression is down-regulated in hepatocellular carcinoma.