U2OS PML-/- cells were reconstituted with YFP-PML-V of three types: WT, A216T or L217F. These cell lines were used to purify YFP-PML bodies using anti-GFP nanobody beads from cells either treated or not with arsenic (1uM for 2h). Protein samples were monitored for PML post-translational modifications and associated proteomes to try to understand why people with acute promyelocytic leukaemia that is resistant to arsenic treatment have these mutations.