GJB1 and renal cell carcinoma: In a study investigating the methylation status of Cx32 promoter and its role as tumor suppressor gene in RCC occurring in hemodialysis patients, 19 tumors and 19 matched non-cancerous tissues of kidneys from hemodialysis patients along with 10 matched pairs of RCC tumors and normal tissues from general patients who did not have any hemodialysis were studied.