MAP2K7 (MKK7) is a dual-specificity protein kinase that serves as an essential component of the stress-activated JNK signaling pathway 1. Along with MAP2K4, MAP2K7 is one of only two kinases known to directly activate JNK1, JNK2, and JNK3 by phosphorylation, with MAP2K7 showing preferential phosphorylation of the threonine residue in the Thr-Pro-Tyr motif 1. This monophosphorylation is sufficient to trigger JNK activity, making MAP2K7 crucial for initiating JNK signaling in response to stress signals including inflammatory cytokines, osmotic stress, and genomic damage 1. In cancer, MAP2K7 exhibits complex roles depending on context. Loss-of-function mutations in MAP2K4 and MAP2K7 genes are found in HER2+ breast cancer, and JNK pathway deficiency promotes HER2+-driven breast cancer development 2. However, MAP2K7 can also promote tumor progression, as elevated expression correlates with higher histological grades in colorectal cancer and increased lymph node metastasis 3. The protein participates in diverse cellular processes including senescence and extracellular matrix metabolism through signaling axes like BRD4/MAP2K7/PGF in intervertebral disk degeneration 4, and can be regulated by methylation via EEF1AKMT3, affecting TP53 stability in gastric cancer 5. These findings highlight MAP2K7's potential as a therapeutic target, with growing interest in developing specific MAP2K7 inhibitors for cancer treatment 1.