GJC1 (gap junction protein gamma 1, also known as connexin45) encodes a structural component of gap junctions, specialized intercellular channels that enable passage of small molecules and electrical signals between neighboring cells 1. GJC1 forms both homotypic and heterotypic channels and is expressed across diverse tissues including chondrocytes, cardiac tissue, and bladder 2. Beyond its canonical gap junction function, GJC1 mediates innate immune signaling by translocating second messengers like 2',3'-cGAMP between virus-infected cells and macrophages to amplify antiviral responses. Loss-of-function mutations in GJC1 impair channel coupling conductance and subcellular localization, contributing to cardiac arrhythmias; a heterozygous mutation (M235L) segregated with familial atrial fibrillation and conduction disease in a Chinese kindred 3. GJC1 has emerged as a potential oncogenic biomarker, with elevated expression in papillary thyroid carcinoma (AUC=0.982 in GEO dataset) and in liver cancer cells under high-glucose conditions, where O-GlcNAcylation-dependent mechanisms enhance proliferation 45. Additionally, de novo nonsense mutations in GJC1 have been identified in schizophrenia patients, with evidence suggesting GJC1 dysfunction may impair glutamatergic neuron ion channel regulation during prenatal neurodevelopment 6. GJC1 is also upregulated in overactive bladder tissue 7.