XBP1 and melanoma: Furthermore, concerning SIRT7-regulated PD-L1 expression via the IRE1α-XBP1 axis, we pre-treated SIRT7-overpressed melanoma cells with IRE1α inhibitor STF083010 and XBP1 inhibitor Toyocamycin respectively in the co-culture system to see whether IRE1α and XBP1 participate in endowing SIRT7-overpressed melanoma cells the capacity to mitigate the function of CD8+T cells.