SEK1 also known as MEK4, MKK4, MAP2K4 is a member of the mitogen-activated protein kinase (MAPK) family. SEK1 plays a crucial role in the mitogen-activated protein kinase (MAPK) signaling pathway by specifically activating both p38 and c-Jun N-terminal kinase (JNK) MAP kinases, which are essential for cellular responses to stress, inflammation, and apoptosis. The activation of these kinases is vital for regulating various physiological processes, including cell differentiation, proliferation, and survival, making SEK1 a significant player in cellular signaling networks. Understanding SEK1 function and interactions within the MAPK pathway can provide insights into the mechanisms underlying various diseases, including cancer and neurodegenerative disorders.