RCAN1 and Alzheimer disease: The mechanism behind the early onset of AD pathology is not fully understood, but in this paper, we report that the overexpression of certain genes on chromosome 21, particularly in the Down syndrome critical region 1 (DSCR1) that includes APP, Cu/Zn superoxide dismutase (SOD1), S100β and RUNX1 transcription factors, play crucial roles [2].