<p>Cellular therapies for several blood cancers particularly of lymphoid origin have made remarkable leaps forward. In parallel, blood proteomics, specifically quantitative proteomics, has been a powerful tool for identifying and quantifying protein biomarkers associated with cellular therapies, providing insights into treatment efficacy and toxicity. Both mass spectrometry (MS)-based proteomics and large-scale affinity-based platforms such as Olink and SomaScan have been increasingly implemented in research and clinical laboratories to identify and quantify candidate biomarkers in the blood. Biomarkers are used for risk stratification, early diagnosis, prognosis, and for treatment response prediction and monitoring in context of treatment efficacy and toxicity. These biomarkers might facilitate timely and selective therapeutic intervention and understand pathogenesis mechanisms of responses and adverse events. They are anticipated to undergo faster transition from bench to bedside soon. This review article summarizes recent technical progresses in clinical proteomics. The review also provides current information on validated biomarkers in the field of cellular therapies.</p>