MAPK8IP1 encodes islet-brain-1 (IB1), a scaffold protein that serves as a critical regulator of JNK signaling and pancreatic β-cell function. The protein functions primarily as a JNK-interacting protein that modulates JNK pathway activation and cellular responses to stress 1. MAPK8IP1 expression is tissue-specific, predominantly found in pancreatic islets and nervous system, controlled by the transcriptional repressor REST through neuron-restrictive silencer elements 1. In pancreatic β-cells, MAPK8IP1 directly regulates GLUT2 and insulin gene expression, with decreased expression leading to reduced insulin secretion and impaired β-cell function 23. The gene serves as a candidate for type 2 diabetes, with functional mutations associated with increased β-cell apoptosis and reduced ability to counteract JNK pathway inhibition of insulin transcription 2. MAPK8IP1 also plays a dual role in inflammasome regulation, correlating positively with key inflammasome-related genes while paradoxically reducing palmitic acid-induced inflammasome activation when silenced 4. Additionally, the protein has been implicated in cancer metastasis, where it acts as a tumor suppressor targeted by miR-10a-5p in gastric cancer 5, and shows therapeutic potential in acute lung injury through modulation of MAPK and PI3K-AKT signaling pathways 6.