Table 1.

Summary of central mechanisms of T-cell desertification and exclusion driving resistance to ICT.

Process	Mechanisms	Impacted ICT	Reference
T-cell desertification	β2M downregulation CD1d/SPI1 epigenetic control	Anti-PD-1/PD-L1	[56, 58].
	Msr1/Clever-1 upregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[29, 31]
	CIITA downregulation	Anti-PD-1/PD-L1	[15]
	HLA-DM deficiency	Potential resistance to ICT	[16]
	Tumour-derived suppressive cytokines	Anti‐CTLA-4, anti-PD-1/PD-L1	[27, 32, 35–38]
	TGF-β upregulation	Anti-PD-1/PD-L1	[37, 38]
	IDO1 upregulation	Anti-PD-1/PD-L1	[39, 40]
	Tumour-induced STAT3 overexpression	Anti-PD-1/PD-L1	[40]
	WNT/β-catenin upregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[42, 43, 46, 47, 61]
	COX-2 upregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[44]
	MIF/CD74 and /CXC axis activation	Anti‐CTLA-4, anti-PD-1/PD-L1	[27, 61, 120]
	BAP1 deficiency	Anti‐CTLA-4, anti-PD-1/PD-L1	[61]
T-cell exclusion	WNT/β-catenin upregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[42, 43, 46, 47]
	MHC molecules downregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[51–53, 55]
	β2M downregulation	Anti‐CTLA-4, anti-PD-1/PD-L1	[56, 57]
	CAFs upregulation	Anti-PD-1, anti-PD-1/PD-L1	[10, 19, 59]