As in our previous assessment of AD and control cases [4], the cerebella of both twins exhibited virtually identical staining patterns and intensity for 5-methylcytosine (Figure 2a), as well as for another methylation marker, 5-methylcytidine (Figure S1) and several methylation stabilizing factors (MBD2/3 and HDAC2; Figure S2). Here, HDAC2 is linked to Alzheimer disease.