||P.5 right column bottom paragraph to p.6 left column 2nd paragraph:"[Investigators] performed a global and unrestricted protein modification search [refs 41, 42] to identify the most frequent post-translational modifications in [their] protein data set (Supplementary Fig. 15). [They] identified 11 different types of modifications (Table 1 and Supplementary Table 17) and confirmed many known lysine acetylation and phosphorylation sites from previous studies focusing on single PTMs [post-translational modifications] [refs 11, 14, 43]. [They] also found that certain modifications are enriched in specific protein classes and pathways (Table 1), and modify proteins of different expression levels (Fig. 5a) and that proteins can carry different types of post-translational modifications at the same residue (Supplementary Table 18). Notably, [they] identified a large number of post-translational modifications, in particular protein methylation and N-terminal protein acetylation sites (Table 1)."