Table 4.

Genes mentioned twice or more in the reviewed studies and the according related SNPs mentioned

Gene	Related SNPs	Role of the gene
ACE2 (angiotensin I converting enzyme 2)	rs75603675, rs2285666, rs879922, rs73635825, rs143936283, rs143936283 rs267606406 rs4646116, rs149039346, rs147311723, rs714205, rs1514283, rs4646175, rs3746444, rs113808830, rs3751304, rs112657409, rs11910678, rs77675406, rs713400, rs13015258, rs12329760, rs775181355, rs762890235, rs35803318, rs41303171, rs774469453, rs773676270, rs2285666, rs146598386, rs73195521, rs755766792, rs2285666, rs6598045	SARS-CoV-2 spike protein entry receptor [15]
IFITM3 (interferon-induced transmembrane protein 3)	rs12252-C, rs6598045	Gene variants of IFITM3 are related to the infection of influenza and viruses. IFITM3 is significant in taking antiviral actions. It prevents cellular lipid bilayer from getting bisected by viruses [7]. Immune effector protein that is significant to the restriction of a virus is encoded by IFITM3. Also, membrane restriction is done by IFITM3 [8]
TMPRSS2 (transmembrane protease, serine 2)	rs61735794, rs61735792, rs75603675, rs112657409, rs11910678, rs77675406, rs713400, rs13015258, rs12329760	Cleavage of TMPRSS2 activates influenza virus hemagglutinin and the human metapneumovirus F protein [3]