Evaluation of the GJIC efficiency further showed that a significant augmented intercellular delivery of calcein toward C6 glioma cells was only caused by the Cx43-overexpressed MSCs (MSCs-tk (M@P)), indicating the overexpression of Cx43 in MSCs played a critical role to determine the efficiency of GJIC (Figure 3G). The gene discussed is TKT; the disease is glioma.