MAP3K12 (also known as DLK - dual leucine zipper kinase) functions as a serine/threonine protein kinase that plays crucial roles in both physiological neuronal development and pathological processes. The protein operates within non-canonical MAPK signaling pathways, particularly activating JNK/SAPK cascades through downstream effectors like MAP2K7 and MAPK1/ERK2 1. MAP3K12 is essential for neuronal development and axon regeneration, but paradoxically also mediates neurodegeneration 2. In neurodegenerative contexts, MAP3K12 activation leads to phosphorylation of transcription factor ATF2, which drives pro-apoptotic transcriptional responses in neurons 3. The kinase also contributes to cancer progression through multiple mechanisms. In non-small cell lung cancer, MAP3K12-binding proteins activate JNK pathways that induce matrix metalloproteinase expression, promoting tumor invasion and metastasis 4. In renal clear cell carcinoma, MAP3K12 acts as a tumor promoter, enhancing cell proliferation, migration, and invasion 5. The protein's activity is regulated by microRNA-130a, which targets MAP3K12 to modulate JNK signaling in diabetic endothelial progenitor cells 6. MAP3K12 expression correlates with aggressive clinical behavior in dedifferentiated liposarcoma, linking it to higher metastasis risk and mortality 7. These findings establish MAP3K12 as a critical kinase in both neuronal fate determination and cancer progression.