The careful control of protein expression and phosphorylation modification is essential for normal early erythropoiesis. Erythroid diseases are influenced by dysregulation of protein synthesis or modification. Researchers needed to fully understand the kinetics of protein phosphorylation profiling during human erythroid development. For a study, they described a tandem mass-tagging method for quantitative proteome and phosphoproteomic analysis. 

They constructed 11,414 phosphopeptide expression clusters and phospho-expression profiling systems for early erythropoiesis in humans. Multiple functional modules of phosphoproteins, such as those that regulate the G2/M transition and actively phosphorylated signaling, were discovered using standardized techniques for multitier integrative analysis (e.g., cell cycle-related pathways). 

The results of the further investigation showed that CDK family members were the primary kinases that phosphorylate substrates in erythroid progenitors and that CDK9 was crucial for the proliferation of erythroid progenitors. The phosphoproteomic profiling, integrative network analysis, and functional investigations collectively described phosphoproteome landscapes and identified signaling pathways important for early erythropoiesis in humans. 

The study would be an invaluable resource for future research on the roles of phosphatase and kinase in human erythropoiesis and conditions connected to erythroid.