Several reports have described the relationship of Cx32 with cell proliferation and cyclin D1 expression: (a) proteome analysis indicated that Cx32 indirectly interacted with Erk [28], (b) radiation-induced liver tumors in Cx32 knock-out mice had increased pErk staining compared with that in Wt mice [29], and (c) overexpression of Cx32 decreased cyclin D1 expression and caused G1 arrest in liver cancer cells [30]. Here, GJB1 is linked to liver cancer.