Table 1.

List of selenoproteins, by category, and their potential role in CRC via pre-clinical or clinical data.

Selenoprotein Category	Gene	SNP, relevance for CRC	Role in CRC	Selected References
Glutathione Peroxidases	GPX1	Various, including functional SNPs	Likely, but unclear	[38,44,110,111,167]
	GPX2	Yes, but effect unclear	Implicated in prevention & promotion	[38,52,53,110,111,116,169]
	GPX3	Yes, but effect unclear	Potentially, but unclear	[112,147,148]
	GPX4	Yes, but effect unclear	Potentially, but unclear	[105,177,178]
	GPX6	unknown	unknown	[23]
Thioredoxin Reductases	TXNRD1	Yes, but effect unclear	Implicated in prevention & promotion	[20,47,61,63,71,75,76]
	TXNRD2	Yes, but effect unclear	Potentially, but unclear	[101,178]
	TXNRD3	Yes, but effect unclear	Potentially, but unclear	[101,116]
Thyroid Hormone Deiodinases	DIO1	Yes, but effect unclear	Unknown	[197]
	DIO2	Unknown	Unknown	[35]
	DIO3	Yes, but effect unclear	Likely, possibly through WNT-pathway	[164,197]
ER-resident selenoproteins	SELENOF	Yes, but effect unclear	Implicated in prevention/promotion	[20,76,94,96,127,181,198]
	SELENOI	Unknown	Unknown	[36]
	SELENOK	Yes, but unclear	Unknown	[187,189]
	SELENOM	unknown	Unknown	[92,190]
	SELENON	Yes, associated with rectal cancer	Potentially, but unclear	[101,186,199]
	SELENOS	Yes, CRC risk modified	Likely, possibly through immune response	[100,101,178,182,200]
	SELENOT	Unknown, no evidence	Unknown	[201,202]
Other selenoproteins	SELENOH	Yes, no association with CRC	Unknown	[92,101]
	SELENOO	Unknown	Unknown	[203]
	SELENOV	Unknown, no evidence	Unknown	[23]
	SELENOW	Yes, CRC association via estrogen	Potentially, possibly through cell cycle regulation	[101]
Methionine sulfoxide reductase	MSRB1	Unknown	Likely, through immune response	[149,151,153]
Selenoprotein Synthesis	SEPHS2	Unknown	Unknown	[195]
Selenium Transport	SELENOP	Yes, CRC risk association	Likely, through immune response or WNT-pathway	[21,53,87,169,178,204]