HLA-DRB1 and neoplasm: To explore this further, we assessed the expression of HLA-DRB across tumors and found higher expression in tumor regions than in stroma regions, specifically in the LUAD patients 03421 and 02672 (Fig. 4b), in whom HLA-II molecules were indeed immunolocalized to the membrane of tumor cells (assigned as HLA-II+ tumors; Fig. 4c).