Xp Mitogen Activated Protein Kinase (MAPK) is a vital component in cellular signaling pathways, regulating various biological processes. Synonyms for this key protein involve different terminologies used interchangeably to denote its functions. These synonyms include Extracellular Signal-Regulated Kinase (ERK), p42/p44 MAPK, Mitogen-Activated Protein Kinase 1 and 3 (MAPK1/3), or Mitogen-Activated Protein Kinase 3 and 6 (MAPK3/6). Each of these synonyms refers to the same enzyme that plays a crucial role in transmitting signals from the cell surface to the nucleus, ultimately controlling gene expression and participating in cell proliferation, differentiation, and survival. Understanding these synonyms aids in comprehending the extensive research conducted on Xp Mitogen Activated Protein Kinase and its implications in various physiological and pathological processes.