Whether GITRL is upregulated in solid tumors is still an open field, since its expression has been found in AML [31] and in some cell lines such as HUVEC EA.Hy926 or EBV-transformed B cell [70], but no study is so far available about GITRL expression in murine or human solid tumors (Figure 2). This evidence concerns the gene TNFSF18 and acute myeloid leukemia.