CD274 and melanoma: Given that melanoma cell lines and patient tumours occasionally exhibit dysfunctional IFN signalling due to genetic defects [39,40,41,42,43], we additionally verified, by PD-L1 upregulation upon IFNγ treatment, that ten low PD-L1IND cell lines in our panel were inducible, which confirmed them as being able to respond to IFNγ induction (Figure S1D), while PD-L1CON weren’t inducible [38].