Increased CD3+ T-lymphocyte and CD8+ T-cell tumor infiltration in RANK−/− tumors compared with RANK+/+ was confirmed by IHC (Fig. 2b, c) and the mRNA levels of the cytotoxicity markers, namely Ifnγ and perforin (Prf1) were higher in RANK−/− tumors (Fig. 2d). This evidence concerns the gene PRF1 and neoplasm.