Independent from vemurafenib resistance, the curcumin-harmine-isovanillin combination drug GZ17-6.02 upregulated class I MHCA and suppressed PD-L1 in PDX BRAFV600E melanoma cells, which was mediated by the downregulation of several HDACs (HDAC3, HDAC5, HDAC6, HDAC7, and HDAC8). Here, HDAC5 is linked to melanoma.