In fact, most published studies characterizing ACP mutant CP proteins from a functional perspective have so far focused on the GPI-anchored form of the protein.18, 54, 55 ACP has a clinical landscape characterised by both central nervous system (CNS) and peripheral phenotypes, including iron-restricted erythropoiesis leading to anaemia,1 and systemically delivered CP mitigates both CNS and non-CNS phenotypes in Cp-KO mice (a translational in vivo model of human ACP15,16). This evidence concerns the gene CP and anemia (phenotype).