To discard possible artefacts induced by overexpression of Cx43 in HEK293 cells, we employed and validated our nuclei purification protocol in multiple cell lines with endogenous expression of Cx43, which demonstrated that full-length Cx43 is also present in purified nuclei of cardiomyoblast rat H9c2, cancer human C33a and renal epithelial rat NRK cells (electronic supplementary material, figure S1d). The gene discussed is GJA1; the disease is cancer.