HLA-B and COVID-19: One study assessed HLA frequencies in a cohort of Greek COVID-19 patients and identified a possible negative association of HLA-B*52 in hospitalized patients, suggesting a protective role for this allele against disease severity.23 Additionally, Kiyotani et al investigated the possible peptide epitopes that seem to have a high affinity to HLA class I and II molecules to induce the CD8 + and CD4 + T-cell- related immune responses.