BAP1 and cancer: In line with previous observations in BAP1 knockout mouse ESCs and human cancer cell lines (Wang et al. 2018; Campagne et al. 2019; He et al. 2019; Kolovos et al. 2020), Western blot analysis showed that H2AK119ub1 levels were markedly increased following BAP1 removal, whereas H2BK120ub1 was unaffected (Fig. 1B).