Table 8.

Previous studies for the association between the IL6R and TNF polymorphism with COVID‐19

Gene	SNP	Results	References
IL6R	rs2228145	The prevalence of the A and C alleles were 0.673 and 0.327, respectively.	Strafella et al. (2020)
IL6R	rs2228145	The frequency of AC genotype was higher in populations of Japan, Spain, Mexico, Brazil, Russia, Poland, Italy, and the Netherland, while the AA genotype was more frequent in from Indian, Swedish and South Africa populations. The CC genotype was only observed in the UK population.	Karcioglu Batur and Hekim (2021)
IL6R	rs2228145	The rs2228145 polymorphism elevated serum sIL‐6R concentrations in subjects with heterozygous or homozygous genotypes.	Garbers et al. (2018)
IL6R	rs2228145	Frequency of the CC genotype was higher compared with the AC and AA genotypes in a population.	Smieszek et al. (2021)
TNFA	rs1800629	The AA genotype of TNFA is related with a high aggressive pattern of the disease.	Saleh et al. (2020)
TNFA/TNFB	rs1800629 rs909253	The association between TNFA/TNFB polymorphisms and COVID‐19 disease.	Heidari Nia et al. (2021)

Abbreviation: SNP, single‐nucleotide polymorphism.