As the performance of mass spectrometer (MS) and large-scale protein sequencing has been improved over the last few years,pushing the proteome analysis to the level that is compatible to mRNA-seq.The development of affinity-based reagents that target sub-proteomes that may correlate with activities,such as transcription factor (TF) DNA binding activity and post-translational modification (PTM) (especially for phosphorylation,ubiquitilation,and acetylation) has further extended proteomics to low abundant but functionally important regime.