Unexpectedly, even CD8+ and CD4+ T infiltrating lymphocytes as well as the CD8+/CD44high activated T lymphocytes were significantly higher in B16-B1A tumours with respect to B16-pEF1 ones (Figures 5(c)–5(e)); no differences were observed in the population of CD4+/CD44high T lymphocytes (Figure 5(f)). Here, CD4 is linked to neoplasm.