USP28 and cancer: Functions of USP28 in different cancer cell types reveal a variety of cancer-relevant effects of USP28: it elicits stem-cell-like characteristics through LSD1-stabilization [61], it acts on p53 and GATA4, affecting cellular senescence [64], it impacts on cell proliferation through deubiquitination of histone H2A [62], and it sensitizes cells to DNA-damage via its interactions with 53BP1 and claspin [59].