TABLE 2.

The ABC scoring system developed by NIA-AA.

Assessment	NIA-AA scoring
Aβ plaques	A0 (not)
	A1 (low)
	A2 (intermediate)
	A3 (high)
NFTs, including pretangles and threads	B0 (not)
	B1 (low)
	B2 (intermediate)
	B3 (high)
Neuritic and diffuse plaque density	C0 (not)
	C1 (sparse)
	C2 (moderate)
	C3 (frequent)

The scoring system can be used to help assess and validate the neuropathological features of AD in mouse lines that are potential preclinical models for AD research. Reproduced with permission from Keene et al. (2016). NIA-AA, Alzheimer’s Association; Aβ, amyloid-β; NFT, neurofibrillary tangle.