AQP	aquaporin
BG	Bowman’s gland
CNS	central nervous system
CSF	cerebrospinal fluid
GOB	globose basal cell
HBC	horizontal basal cell
HIV	human immunodeficiency virus
Ig	immunoglobulin
MALT	mucus-associated lymphatic tissue
M cell	microfold cell
MUC	mucin
N2B	nose-to-brain
NALT	nasopharynx-associated lymphatic tissue
OC	occludin
OE	olfactory epithelium/olfactory mucosa
OEC	olfactory ensheathing cell
OSN	olfactory sensory neuron
Pa·s	Pascal·second (unit of viscosity)
PEG	polyethylenglycol
PLA	poly lactic acid
PLGA	poly(lactid-co-glycolid) acid
RE	respiratory epithelium/respiratory mucosa
SUS	sustentacular cell
ZO	zonula occludens