Then we have explored the relationship between the expression of HLA-B, HLA-A, HLA-DRA, IDO1, TAGAP, CIITA, PRF1 and CD8B at transcriptional level and the tumor infiltrating immune cell populations (B cells, CD8 + T cells, CD4 + , T cells, neutrophils and dendritic cells). The gene discussed is IDO1; the disease is neoplasm.