WDR5 and pachyonychia congenita: In PC cell lines, the IFN-γ-induced PD-L1 mRNA and protein levels were significantly abrogated by knockdown of the histone methylation regulators WDR5 or MLL1 (not by C-MYC silencing); WDR5 seemed important for PD-L1 transcription, while OICR-9429 (antagonist of WDR5 interactions with MLL1, C-MYC, and other partners) blocked this process [10].