Endothelial cell dysfunction is the initial step in atherosclerosis, in which gap junction proteins such as connexin 40 (Cx40) might play an important role. Previously, we could demonstrate that miRNA-26b, a 21-nucleotide miRNA, is highly expressed in human atherosclerotic plaques and plays a key causal role in atherogenesis. There is evidence that miRNA-26b and Cx40 play crucial roles in sustaining endothelial health. However, their potential effects on atherosclerosis-related processes remain poorly understood. Therefore, this study elucidated the expression of miRNA-26b and Cx40 and studied the effect of Cx40 on inflammation and monocyte binding, which are key processes in atherosclerosis formation. In a human in vitro endothelial cell model, miRNA-26b overexpression is associated with increased Cx40 expression. Although we did not observe any anti-atherogenic effect of Cx40 on monocyte attachment or VCAM-1 transcription under static conditions, a flow-dependent expression pattern characterised by increased Cx40 and reduced VCAM-1 transcription was observed. How miRNA-26b and Cx40 are connected remains to be investigated. Furthermore, the functional role of Cx40 under flow conditions requires further investigation.