B2M and infection: In a previous study in which we sought to identify HLA-C*12:02-restricted HIV-1 epitopes, some of the peptides identified using LC-MS/MS that did not show binding to HLA-C*12:02 in the HLA stabilization assay could be refolded with HLA-C*12:02 heavy chain and β2m molecules in a refolding assay, but T cells specific for these low-affinity peptides were not observed in an ex vivo ELISPOT assay, suggesting that they did not elicit strong T cell responses in natural infection (28).