Updated publication reference for PubMed record(s): 30259924. A standard proteolytic digest of a human protein mixture, prepared at 1.5-fold to 3-fold protein concentration changes, and diluted into a constant background of yeast proteins. Similar to other datasets used for ground truth in quantitative studies, with the exception of being more granular, and much larger in terms of replicates, to enable more rigorous and accurate testing of quantitative algorithms.