GJA1 and neoplasm: The vast majority of sarcoma cells in the middle and outer area of the tumor are positive for the three connexins (Figures 3A,C,E), while in close vicinity of the transition zone the sarcoma cells lost their positive connexin signal (Cx43, Cx40, Cx45), which indicated that the tumor cells at the border do not express any of the cardiac connexins (Figures 3B,D,F).