G2E3 (G2/M-Phase Specific E3 Ubiquitin Protein Ligase): G2E3 is a gene that encodes an E3 ubiquitin ligase involved in regulating the cell cycle, particularly during the G2/M phase transition. It aids in tagging proteins for degradation, thereby controlling key cell cycle regulators. Dysregulation of G2E3 can lead to cell cycle disturbances and may contribute to the development of cancer.