Table 1.

Mechanisms of defective T-cell priming

Mechanisms	Examples	References
Lack of tumor antigens	Lack of neoantigens	16
	Low mutational burden	16, 17
Insufficient antigen processing or presentation	Deletion of B2M	24, 25
	Deletion of TAP	23
	Loss of MHC class I (Lysosomal pathway)	26
Dysfunction of DC-T cell interaction	Loss of BATF3 DCs	32
	Impaired DC activation (Loss of FLT3L or GM-CSF)	35
	Overexpression of cosuppressive signals (CTLA-4)	28
	Overexpression of STC1	29