A
AEMPS	Spanish Agency of Medicines and Medical Devices
ACE 2	Angiotensin-Converting-Enzime II
ALI	Acute lung injury
ANG	Angiotensin
ANGPT	Angiopoietin
ARDS	Acute respiratory distress syndrome
AT	Adipose Tissue
AT-MSC	Adipose Tissue-Derived Mesenchymal Stem Cells
B
BCL2	B-cell leukemia/lymphoma 2 protein
BM	Bone Marrow
BM-MSC	Bone Marrow-Mesenchymal Stem Cells
BNDF	Brain-Derived Neurotrophic Factor
C
CAT	Catalase
CC	Chemoattractant cytokines
CCL C-C	C-C motif chemokine ligand
CD	Cluster differentiation
CDKN	Cyclin-Dependent Kinase Inhibitor
COPD	Chronic Obstructive Pulmonary Disease
COVID-19	Coronavirus Disease-2019
CRISP-Cas	Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated
COX 2	Ciclooxigenase 2
CXC	C-X-C Motif Chemokine
CXCL	C-X-C Motif Chemokine Ligand
D
DC	Dendritic Cell
DNA	Deoxyribonucleic acid
DP-MSC	Dental Pulp Derived Mesenchymal Stem Cells
E
ECM	Extracellular matrix
EGF	Epidermal Growth Factor
EMT	Epithelial-Mesenchymal Transition
EV	Extracellular Vesicle
F
FDA	Food and Drug Administration
FGF	Fibroblast Growth Factor
G
GF	Growth Factor
GM-CSF	Granulocyte-Macrophage Colony-Stimulating Factor
GPx	Glutathione Peroxidase
GTP	Guanosine triphosphate
GvHD	Graft-versus Host Disease
GSH	Glutathione
H
HLA	Human leukocyte antigen
hAMSC	Human amniotic membrane stem cells
HGF	Hepatocyte Growth Factor
HSP70	Heat Shock Protein 70
hTERT	Human Telomerase Reverse Transcriptase
hUCESC	Human Uterine Cervical Stem Cells
I
ICAM	Intercellular Adhesion Molecule
ICU	Intensive Care Unit
IDO	Indoleamine 2,3-dioxygenase
IFN-α	Interferon alfa
IFN-β	Interferon beta
IFN-γ	Interferon gamma
IFI	Interferon-inducible protein
IFITM	Interferon-Induced Transmembrane Family
IGF	Insulin-Like Growth Factor
IL	Interleukine
ILRA	Recombinant IL-1 receptor antagonists
ISG	Interferon Stimulated Genes
ISSCR	International Society for Stem Cell Research
K
Kg	Kilogram
KGF	Keratinocyte growth factor
L
LPS	Lipopolysaccharide
M
μm	micrometer
MCP	Monocyte Chemoattractant Protein
MIF	Migration Inhibitory Factor
MIP	Macrophage inflammatory Protein
MMP	Matrix Metalloprotease
mRNA	Messenger Ribonucleic Acid
MSC	Mesenchymal Stem Cells
N
nm	Nanometer
NFkβ	Nuclear Factor Kappa B
NIH	National Institutes of Health
NO	Nitric Oxide
P
PDGFα	Platelet-derived Growth Factor α
PD-MSC	Periosteum-derived Mesenchymal Stem Cells
PGE2	Prostaglandin E2
PMAIP	Phorbol-12-myristate-13-acetate-induced protein 1
PaO2/FiO2	Partial Pressure of Arterial Oxygen to Fraction of Inspired Oxygen Ratio
R
Rab	GTPases
RANTES	Regulated upon Activation, Normal T-cell Expressed and Secreted
RNA	Ribonucleic Acid
S
SARS-CoV-2	Severe acute respiratory syndrome coronavirus 2
SAT	Spermidine/spermine-N1-acetyltransferase
SOD	Superoxide dismutase
SIRT	Sirtuin
T
TGF α	Transforming growth factor α
TGF β	Transforming growth factor β
TLR	Toll-Like Receptors
TMPRSS2	Transmembrane protease serine 2 protein
TNF-α	Tumor necrosis factor α
TUNEL	Terminal dUTP Nick End Labeling
U
UC	Umbilical Cord
USA	United States of America
USD	United States Dollar
V
VC-MSC	Villous Chorion-Derived Mesenchymal Stem Cells
VEGF	Vascular Endothelial Growth Factor
W
WJ	Wharton’s-Jelly
WHO-ICTRP	World Health Organization-International Clinical Trial Registry Platform
3D	Three-Dimensional