B2M and COVID-19: Unsurprisingly, the “near to epithelial cell” myeloid population shows higher COVID-19 signatures score (Fig. 6d) and highly expresses multiple MHC Class I and II related genes, such as B2M, HLA-A, HLA-B, HLA-C, HLA-E, and HLA-DRA, which are associated with the interferon (IFN) response (Supplementary Fig. 30f).