B2M and Hodgkins lymphoma: In our study, genes related to major histocompatibility complex (MHC) class I and II machinery/biosynthesis such as HLA-DRA, CTSS, HLA-DPA1, HLA-DPB1, CTSC, B2M genes were expressed at higher levels in the mixed-cellularity subtype than in nodular sclerosis subtype at diagnosis.