We studied anti‐HA immunosignals in three different brains regions: the hippocampal subiculum (Figure 2b), cortical layer 5 (Figure 2c), as these two regions are severely affected by the amyloid pathology in AD mice at a later age, and the hippocampal CA3 (Figure 2d) as it is a region where we previously showed extranuclear but nonsynaptic SUMO1 punctates along MAP2‐positive processes (Tirard et al., 2012). Here, MAP2 is linked to Alzheimer disease.