WFS1 and diabetes mellitus: To investigate whether the misregulation of the cytokine profile could be directly ascribed to the loss of function of WFS1 and to exclude the possibility of other causative factors (i.e. the presence of DM in the WS patient), we transfected PBMCs of healthy donors with a small interfering RNA (siRNA) specific for WFS1 (siWFS1) (Fig. 4A).