MPO and Alzheimer disease: used an 5XFAD mouse model of AD with MPO-deficient mice and mice with haematologic MPO deficiency (5XFAD-MPO-KO), and behavioural tests revealed significantly superior performance in spatial learning and memory, associative learning and anxiety/risk assessment behaviour compared with 5XFAD mice transplanted with WT cells (5XFAD-WT).