% ID/cc	percentage of injected dose per cubic centimeter of tissue
% ID/g	percentage of injected dose per gram of tissue
225Ac	Actinium-225
APP	amyloid peptide precursor
BBB	blood–brain barrier
BTB	brain-tumor barrier
CDR	complementary-determining region
CH1/CH2/CH3	constant domain 1/2/3 of heavy chain
CNS	central nervous system
GFAP	glial fibrillary acidic protein
GFP	green fluorescence protein
HCAb	heavy-chain antibody
HER	human epidermal growth factor receptor
131I	Iodine-131
ID	injected dose
IGF1R	insulin-like growth factor 1 receptor
IgG	immunoglobulin G
111In	Indium-111
NMDAR	N-Methyl-D-Aspartate receptor
PDL1	program death-ligand 1
PET	PET
RMT	receptor-mediated transcytosis
sDAb	single-domain antibody
99mTc	Technetium-99m
TfR	transferrin receptor
VCAM1	vascular cell adhesion molecule 1
VCAMelid	VHH against VCAM1
VEGF	vascular endothelium growth factor
VH	variable domain of conventional antibodies heavy chain
VL	variable domain of conventional antibodies light chain
VHH	variable domain of heavy-chain antibodies
VHHs	plural of VHH
VNAR	variable new antigen receptor
WT	wild-type
89Zr	Zirconium 89