This antigenic peptide transfer mechanism has also been observed between gut-resident antigen-presenting cells (APCs) [11] and, in addition, it was suggested that the Cx43-mediated transfer of antigenic peptides from melanoma cells to dendritic cells (DCs) could be the major mechanism of tumor-associated antigen cross-presentation occurring in vivo, leading to the activation of tumor antigen-specific cytotoxic T lymphocytes (CTLs) and the subsequent elimination of the tumor [12,13]. The gene discussed is GJA1; the disease is melanoma.