MDK and amyloidosis: Additionally, in the 5xFAD amyloidosis mouse model (also termed FAD for simplicity), which overexpresses mutant human APP and PSEN1 genes31, MDK accumulation was observed to be higher in FAD mice than in wild type (WT), corroborated by antibody-based detection of MDK in mouse plaques (Extended Data Fig. 1a, 1b, 1c).