CD274 and melanoma: Skmel5 TPC2 KO cells mirrored the HCC phenotype, showing elevated MHC-I and reduced PD-L1 expression (Supplementary Figures S4C, D), whereas B16F10luc cells remained largely unaffected (Supplementary Figures S4C, E), correlating with the more substantial tumour weight reduction observed in the HCC model compared to melanoma (Supplementary Figures S2L, N).