This experiment aimed to characterise ubiquitin chain linkage preferences generated and autoubiquitination sistes during ZNFX1 E3 reactions using diGly remnant mass spectrometry. GlyGly-modified lysine residues were identified as a qualitative proxy for ubiquitin linkage types. Spectral counts of rank-1 GlyGly-modified peptides were used to infer relative linkage abundance. Data interpretation was qualitative in nature, with no quantitative normalisation or statistical comparison applied.