IRF1 and melanoma: The inhibition of MET [62] and JAK/STAT/IRF1 signaling by 15-deoxy-delta12,14-prostaglandin J2 [63] was sufficient to inhibit the IFN-γ-dependent upregulation of PD-L1 in melanoma cells [62], indicating the importance of other regulators of IFN-γ-dependent immune checkpoints in melanoma cells.