GJA1 and breast cancer: 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).