AGREE-II	Appraisal of Guidelines for Research and Evaluation, version II
AJCC-8	American Joint Committee on Cancer, 8th edition
AMSTAR-2	A Measurement Tool to Assess Systematic Reviews, version 2
BCC	Basal cell carcinoma
BWH	Brigham and Women’s Hospital tumour staging for cSCC
CAF	Cancer-associated fibroblast
CDKN2A	Cyclin-dependent kinase inhibitor 2A
cSCC	Cutaneous squamous cell carcinoma
DSS	Disease-specific survival
EADO	European Association of Dermato-Oncology
ECM	Extracellular matrix
EDF	European Dermatology Forum
EMT	Epithelial–mesenchymal transition
GBD	Global Burden of Disease
GLI1/GLI2	Glioma-associated oncogene transcription factors 1 and 2
HHI	Hedgehog pathway inhibitor
HPV	Human papillomavirus
JBI	Joanna Briggs Institute
KC	Keratinocyte carcinoma
LOX	Lysyl oxidase
LVI	Lymphovascular invasion
MMP	Matrix metalloproteinase
MMS	Mohs micrographic surgery
NCCN	National Comprehensive Cancer Network
NMSC	Non-melanoma skin cancer
NOTCH	Notch signalling pathway
OS	Overall survival
PD-1/PD-L1	Programmed cell death protein 1/its ligand
PECO	Population–Exposure–Comparator–Outcome
PNI	Perineural invasion
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PTCH1	Patched 1 receptor
RT	Radiotherapy
SMO	Smoothened receptor
TIMP	Tissue inhibitor of metalloproteinases
TMB	Tumour mutational burden
TME	Tumour microenvironment
TP53	Tumour protein p53
UV	Ultraviolet radiation