USP1 and neoplasm: USP1 inhibitors are also now of interest given the role of USP1 in controlling multiple DNA damage response (DDR) pathways [27,28,55], and the reported overexpression of USP1 in certain tumour types (including sarcomas (reviewed in [29])), suggesting that inhibition of USP1 will remove a key node controlling various points of the DDR, leading to genomic catastrophe and cancer cell death.