Expression of RCAN1, which encodes the regulator of calcineurin 1 and the only gene when knocked out resulted in three AD-related phenotypes in Drosophila, is increased in AD brain [51], and overexpression of the human RCAN1.1S isoform inserted in mice promotes early age-dependent memory and synaptic plasticity deficits and mitochondrial dysregulation leading to tau pathology [52]. Here, MAPT is linked to Alzheimer disease.