IFNG and metastatic melanoma: The loss of ICAM-1 in melanoma cells, which has been used to distinguish between primary and metastatic melanoma, promotes PI3K/AKT signaling and thereby protection from lysis by melanoma antigen probed CTLs, however, treatment with interferon gamma can induce ICAM-1 expression on these metastatic melanomas and reestablish susceptibility to CTL lysis.56 It is tantalizing to suggest that interferon gamma treatment to prime CTLs, coupled with immunotherapy may be a useful approach to treat melanoma patients with low ICAM-1 and low PMEL expression.