Table 6.

Basic information of studied SNPs.

Gene	Chromosome location	SNPs	SNP ID rs number	Region	Function	MAF in European population
SOD2	6	c.47 C > T (p.Val16Ala)	rs4880	Exon	This polymorphism causes a substitution of Val to Ala in codon 16 at position 9 and in consequence, leads to functional modulation of protein; the 16Ala variant with α-helical structure shows normal transportation of the enzyme into the mitochondria, while the 16Val-containing precursor, which has a β-sheet conformation has 30–40% reduced enzymatic activity	C: 0.498
CAT	11	c.-89 A > T	rs7943316	5′ UTR	The T/T genotype of this SNP is associated with a reduction in catalase activity compared to the A/A and A/T genotypes68	A: 0.349
GPX4	19	c.660 T > C (p.Leu220 =)	rs713041	3′ UTR	This polymorphism causes the change of the amino acid at position 220 from leucine to leucine (p.Leu220) in a region of the GPX4 corresponding to the 3′-untranslated region (3′-UTR) of the mRNA and alters the protein binding to the 3′-UTR and reporter gene activity, which in turn modulates the ability of the GPX4 3′UTR both to promote GPX4 synthesis and to compete for components of the selenoprotein synthetic machinery, and thus influence the synthesis of a range of selenoproteins. Summarizing, this SNP is involved in the modulation of the GPX4 synthesis by altering the affinity of the selenocysteine insertion machinery for its SECIS element65,69	T: 0.452
NOS1 (nNOS)	12	g.117803515 C > T	rs1879417	Intron	SNPs, which are localised in intron can affect the mRNA/protein splicing process, resulting in the formation of different isoforms of a protein41,42	C: 0.459
NOS2 (iNOS)	17	c.1823 C > T (p.Ser608Leu)	rs2297518	Exon	This polymorphism causes an amino acid substitution from serine to leucine which increases iNOS activity (alters iNOS protein function) and conferees higher NO production based on the A-allele43	T: 0.198