Updated publication reference for PubMed record(s): 31857848. Analog-sensitive kinase technology allows for specific inhibition of a given kinase. Here we utilize an analog-sensitive CDK9 cell line to determine the impact of CDK9 inhibition on the phospho-proteome of human cells. Specifically, we aim to identify substrates of CDK9 in a quantitative way using stable isotope labeling by amino acids in cell culture (SILAC) followed by LC-MS/MS.