GJA1 and infection: Our previous study showed that the different virulence of MTB infection could induce host macrophage apoptosis in vivo[27] and that apoptosis may be due to the activation of the mitochondrial apoptotic pathway.[28] In this in vitro study, H37Rv infection induced host RAW264.7 macrophage Cx43 expression, and we also found an increasing apoptosis ratio and mitochondrial dysfunction.