It was shown that a complex formed by SEPT4, DYRK1A and α-synuclein may contribute to the development of α-synuclein-positive cytoplasmic aggregates characteristic of PD and, since SEPT4 has been found in neurofibrillary tangles, SEPT4/DIRK1A is also involved in the pathology of AD [94,95,96]. The gene discussed is DYRK1A; the disease is Alzheimer disease.