Figure 4:

Protein quantification is independent from peptide mass or length. Distributions of (A) molecular mass and (B) amino acid sequence length; smaller and shorter proteins are the most prevalent. When plotting peptide mass or length against protein LFQ intensity (C, D) or protein copy number (inferred as in [6]) (E, F), weak (if any, see R² values on figurines) correlations are observed, suggesting that protein abundance estimation is not biased by peptide mass or length (also see Fig. 2B).