CD28 and malaria: Examining genotypic frequency of the CD28 (snp: -372G/A; rs35593994) gene polymorphism, we observed a higher frequency of homozygous mutant variants (-372A/A), though statistically insignificant in the control group compared to the malaria-infected group (16.8% versus 12.4% for the control and malaria groups, respectively) (Table 2); however, this difference was statistically insignificant.