Apart from formation of heterodimer between Jun and Fos proteins, homodimerization of Jun proteins is also known to form active AP-1 complex but complete absence of cJun in supershift assays indicate that cJun do not participate in functional AP-1 complex formation and hence no jun homodimer formation takes place in ESCC. The gene discussed is FOSB; the disease is esophageal squamous cell carcinoma.