GJA1 and triple-negative breast carcinoma: Note thatwe have previously established and characterized these three subsetsof MDA-MB-231 cells with silenced or upregulated Cx43 expression,recapitulating a triple-negative breast cancer in vitro model of the same cell line lineage with varying metastatic potential.18,19 The expression of Cx43 was routinely assessed with qPCR in sortedcells and compared to the expression of Cx43 in MDA-MB-231 cells andWT cells (control), as depicted in Figure S1.