AF cells showed an apparent though not significant increase in mTOR phosphorylation (1.60 ± 0.73 relative signal intensity, p = 0.25) upon transfection with miR-155-5p mimics and a similar trend under inflammation in ERK1/2 phosphorylation (1.54 ± 1.07 relative signal intensity, p = 0.36) (Fig. 4c). Here, MAPK3 is linked to atrial fibrillation.