HLA-DRB1 and lymphoma: B cells were isolated and immortalized from PBMC samples of three lymphoma patients, respectively Pt.2 (HLA-DRB1*0701), Pt.5 (HLA-A*0201 and HLA-DRB1*0701), and Pt.7 (HLA-A*0201 and HLA-DRB1*0701).