GJA1 and glioblastoma: It was also found that the over-expression of cx43 was able to enhance drug sensitivity in human glioblastoma cells [73], by decreasing expression of the bcl-2 protein and significantly enhancing apoptosis during exposure to chemotherapeutic drugs, and interestingly, the action of cx43 seemed not to be directly related to GJIC [73] as was also shown in MCF-7 cells [93].