TNF and melanoma: We demonstrated that DGKα is expressed in several human melanoma cell lines including AKI but not in noncancerous normal human epidermal melanocytes and that the isozyme suppresses tumor necrosis factor-α-induced apoptosis of AKI melanoma cells through the activation of nuclear factor-κB (NF-κB) [11], which is an antiapoptotic factor (Figure 2).