PD-1	programmed cell death protein 1
CTLA-4	cytotoxic T-lymphocyte-associated protein 4
ICIs	immune checkpoint inhibitors
TME	tumor microenvironment
RT	radiotherapy
TAAs	tumor-associated antigens
MRI	magnetic resonance imaging
ERK	extracellular signal-regulated kinase
MAPK	mitogen-activated protein kinase
NF-κB	nuclear factor kappa B
HNSCC	head and neck squamous cell carcinoma
R/M	relapsed/metastatic
ACT	adaptive cell therapy
HPV	human papillomavirus
FDA	US Food and Drug Administration
ORR	overall response rate
BOR	best overall response
Tregs	regulatory T cells
HNCs	head and neck cancers
MDSCs	myeloid-derived suppressor cells
tTregs	thymus-derived Tregs
pTregs	periphery-derived Tregs
FOXP3	Forkhead Box P3
OS	overall survival
EFS	event-free survival
CI	confidence interval
TILs	tumor-infiltrating lymphocytes
HR	hazard ratio
BM	bone marrow
DCs	dendritic cells
CTLs	cytotoxic T lymphocytes
NK	natural killer
NKT	natural killer T cells
TAMs	tumor-associated macrophages
pMN	premetastatic niche
MMP9	matrix metalloprotease 9
MET	mesenchymalepithelial transition
VEGF	vascular endothelial growth factor
GM-CSF	granulocyte–macrophage colony-stimulating factor
TNF-α	tumor necrosis factor α
TCRs	T-cell receptors
TIM-3	T-cell immunoglobulin mucin-3
LAG-3	lymphocyte activation gene 3
VISTA	V domain Ig suppressor of T-cell activation
TIGIT	T-cell immunoglobulin and ITIM domain
PD-L1	programmed death ligand-1
PFS	progression-free survival
mAb	monoclonal antibody
MTD	maximum tolerated dose
CT	chemotherapy
IFN-γ	interferon-gamma IFN-γ
IMRT	intensity-modulated radiotherapy