aSMase	acid sphingomyelinase
AD	atopic dermatitis
CoA	coenzyme A
C1P	ceramide-1-phosphate
C. acnes	Cutibacterium acnes
CerS	ceramide synthase
CLE	corneocyte lipid envelope
DES	dihydroceramide desaturase
ER	endoplasmic reticulum
FA	fatty acid
FAS	fatty acid synthase
FFA	free fatty acid
IL	interleukin
KDSR	3-ketodihydrosphingosine reductase
LCFA	long-chain fatty acid
MAPK	mitogen-activated protein kinase
MCP-1	monocyte chemoattractant protein-1
NADPH	nicotinamide adenine dinucleotide phosphate
NHEK	normal human epidermal keratinocyte
PI3K–Akt	phosphoinositide 3-kinase–Akt
PNPLA1	patatin-like phospholipase domain-containing protein 1
PPARα	peroxisome proliferator-activated receptor α
S1P	sphingosine-1-phosphate
S1PR	sphingosine-1-phosphate receptor
SCFA	short-chain fatty acid
SK	sphingosine kinase
SM	sphingomyelin
SPT	serine palmitoyltransferase
STAT6	signal transducer and activator of transcription 6
TEWL	transepidermal water loss
TGF-β	transforming growth factor-β
TNF-α	tumor necrosis factor-α
ULCFA	ultra-long-chain fatty acid
VLCFA	very-long-chain fatty acid