Enables gap junction channel activity. Involved in several processes, including cellular response to glucagon stimulus; reproductive structure development; and response to steroid hormone. Located in several cellular components, including astrocyte projection; gap junction; and lateral plasma membrane. Used to study hepatocellular carcinoma and lung adenocarcinoma. Biomarker of autoimmune thyroiditis; extrahepatic cholestasis; ischemia; sensorineural hearing loss; and urethral obstruction. Human ortholog(s) of this gene implicated in Bart-Pumphrey syndrome; Vohwinkel syndrome; autosomal dominant keratitis-ichthyosis-deafness syndrome; nonsyndromic deafness (multiple); and palmoplantar keratoderma-deafness syndrome. Orthologous to human GJB2 (gap junction protein beta 2). [provided by Alliance of Genome Resources, Apr 2022]