BRD2 and cyclic hematopoiesis: We identified two subgroups from the 70 CH participants (Fig. 1): 36 had a ratio above or on the cutoff, i.e., those with Normal Aß42/Tau proteins (“CH-NAT”), and 34 had a ratio below the cutoff, i.e. those with Pathological Aß42/Tau proteins (“CH-PAT”).