EXOC4 and Mental deterioration: These were: the exocyst complex component 4 (EXOC4), a component of the exocyst complex which is required for targeting exocytic vesicles to specific docking sites on the plasma membrane and has been associated with rate of cognitive decline in Alzheimer's disease;57 and exostosin glycosyltransferase 1 (EXT1), associated with type I multiple exostoses,58 on chromosomes 7 and 8 respectively.