Notwithstanding these differences in localization and lethality, we observed that these two tumor subsets shared many common biological features, including the expression of CD3 molecules, the heteroclite expression of CD4 and CD8 surface markers, the upregulation of proteins generally involved in proliferation (PCNA) and the lack of expression of TCR–induced markers (i.e., CD69). This evidence concerns the gene CD69 and neoplasm.