CIITA and COVID-19: The molecular interplay between the HLA class II and CIITA in COVID-19 has been demonstrated as follows [20]: CIITA, a master transcriptional regulator, facilitates the peptide-loading machinery and cell surface expression of HLA class II complexes, and has been used to interrogate the HLA class II immunopeptidome of SARS-CoV-2 infected cells and tumors [20].