In fact, gene array analysis has allowed demonstrating that some isoforms, such as Cx26, are able to regulate the expression of angiogenesis-related genes in human breast tumor cells, both in a gap junction-dependent and independent manner [589], whereas Cx43 deficiency has been associated with multiple transcriptional changes in several tissues [590], including the heart [591]. The gene discussed is GJB2; the disease is breast neoplasm.