SEK1/MKK4 Antibody detects endogenous levels of total SEK1/MKK4. MKK4 dual specificity kinase of the STE7 family that phosphorylates and activates JNK1 and -2 as well as p38 but not ERK1 or -2. Mediates cellular responses to various cellular stresses and inflammatory cytokines. Phosphorylation by Akt inhibits MKK4 and suppresses stress-activated signal transduction.