Connexin 43 is a member of the connexin family that is highly expressed in BM‐MSCs.[41, 42] The gap junctions formed by connexin 43 can be inhibited by the mimetic peptide, Gap26.[43] Therefore, we added 0.25 mg ml−1 of Gap26 to the DC of BM‐MSCs and breast cancer cell lines and observed that Gap26 markedly reversed the NK resistance of the cancer cells following MSC‐DC (Figure 2E). This evidence concerns the gene GJA1 and breast carcinoma.