On the basis of GSEA and leading-edge subset analysis, which showed that the presence of TILs was associated with the expression of MHC class I and II genes as part of the antigen processing and presentation pathway, we evaluated immunohistochemical staining of HLA-A, HLA-B/C, and HLA-DP/DQ/DR in 108 advanced-stage serous ovarian cancer patients for whom information on CD8+ TILs was available, part of which was previously published for a larger patient cohort (Leffers et al, 2009a, 2009b). The gene discussed is HLA-B; the disease is ovarian serous adenocarcinoma.