We then applied SCREEN to analyze Jurkat cells treated with Phorbol 12-myristate 13-acetate (PMA) and Ionomycin (PMAi). Analysis of the single cell proteomes under these two treatments show a significant shift in protein abundances, a clear separation between treated and untreated cells, and unique clusters within treated cells are also observed. Analysis of the differentially expressed proteins show multiple pathways being activated due to drug response. Activated pathways are primarily responsible for cell death/differentiation, which indicates that either the majority of the cells were apoptotic at time of sample collection or they started differentiating into other cells types. The separation between the different conditions are shown in Figure with PCA and heatmap plots. To demonstrate that SCREEN has the ability to see a digital response upon drug treatment on a specific area of the proteome using a focused targeted approach, we repeated the experiment with Jurkat cells treated with PMAi for just 30 mins and extracted to 96 well plates. We compared these experimental conditions to Jurkat cells that were treated for 4 hours before extraction to 96 well plates with 4x4 and 2x2 sorting schemes. For this experiment, the HFX Orbitrap mass spectrometer instrument was instructed to target only a limited number of proteins (100 proteins in total) selected from our general Jurkat cells protein library and representing biologically important but low abundant proteins in the human proteome that are related to cell cycle control. We targeted histones, cyclin dependent kinases and kinase inhibitors as well as zinc-finger proteins and cell cycle regulation proteins that are known to be affected by PMAi treatment. Upon database identification by Proteome Discoverer (PD), we identified 165 proteins from these runs, where about 50 proteins appeared to be extra proteins that we did not target. These were mostly keratins and other common lab contaminates, usually present in sample preparation procedure.