Table 4.

Drugs that may regulate the immune checkpoint pathways through targeting ubiquitination/deubiquitination (preclinical)

Type	Name	Target	Preclinical models	References
Proteasome inhibitors	MG132	20S core subunit	In vitro	61,127
	Epoxomicin	20S core subunit	In vitro	128
	Lactacystin	20S core subunit	In vitro	128
E1inhibitors	PYR-41	ubiquitin E1 enzyme	In vitro	60
E3 agonists	Apple polyphenols	MARCH 1	THP-1-derived human DCs	86
DUB inhibitors	Curcumin	CSN5	Breast cancer melanoma colon cancer	53
Others	CDK4/6 inhibitors	Cullin 3SPOP	Prostate cancer	61
	STAT/AKT/ERK inhibitors	c-Cbl, Cbl-b	Lung cancer	43
	EGFR inhibitors	GSK3β, β-TrCP	Breast cancer	52