For instance, IFNα directly promotes PD1 transcription and limits the duration of T cell-mediated immunity in antigen-specific CD8 + T cells.48 Moreover, PDL1 was upregulated by IFNα in BRAF-mutant melanoma cells.49 Our results of upregulation of PDL1 in HNSCC cells and of PD1 in immune cells after IFNα treatment provided us great insights into the ICB resistance associated with anti-PD1/PDL1 treatment failure in HNSCCs. Here, PDCD1 is linked to melanoma.