To investigate whether antigen-presenting cell function is altered with aging and mesothelioma, markers of antigen presentation (MHC-I and II), activation (CD40, CD80, CD86, intracellular IFN-γ, tumor necrosis factor (TNF)-α and IL-12) and regulation (CD39, CD73, A2A receptor (A2AR), A2B receptor (A2BR), programmed cell death ligand-1 (PD-L1), galectin-9 (GAL-9), intracellular IL-10, and transforming growth factor (TGF)-β latency-associated peptide) were compared on CD11c+ cells from young and elderly mice using flow cytometry. This evidence concerns the gene LGALS9 and mesothelioma.