Y box binding protein 1 (YBX1) belongs to the YBX family of transcription factors that contain an ancient and evolutionarily conserved cold shock domain (CSD). The name “cold shock” originates from E. coli, which, when exposed to the stress of cold temperature, increases the expression of around 13 proteins containing the CSD by 2–10 folds. This helps the cell survive in low temperature. 1 This observation found in bacteria is similar to the role of YBX1 in eukaryotic cell's response to stress, indicating the existence of not only structural, but also functional conservation over a wide evolutionary span in the YBX family.