Fig. 8: Graphical summary.

Left panel: In the absence of NOTCH mutations, tumor B cells in proliferative centers constitutively express MHC class II and PD-L1 on their cell surface. Right panel: Mutations in the PEST domain of NOTCH1 or NOTCH2 cause higher NOTCH levels and transcriptional activity, which leads to a significant downregulation of MHC class II proteins through epigenetic suppression of CIITA. PD-L1 levels increase, partly due to enhanced transcription of the interferon-γ-receptor and an autocrine feedback loop involving INFγ. Created with BioRender.com.