GJB1 and breast cancer: The EMT subtype maintains great variability in CNVs, similar to that of human luminal B breast cancer [82], but the gene expression signatures of EMT tumors overlap with the canonical signatures associated with human claudin-low breast cancer: high expression of markers for cytotoxic T-cell and natural killer (NK) cell infiltration (Granzymes C, D, E, F, and G), high expression of dormancy markers (NR2F1), and low expression of cell-adhesion proteins (CLDN2, GJB1, CEACAM1) [83] (Additional file 25: Fig. S21).