The National Cancer Institute (NCI)’s Clinical Proteomic Tumor Analysis Consortium (CPTAC) is a national effort to accelerate the understanding of the molecular basis of cancer through the application of large-scale proteome and genome analysis, or proteogenomics. NCI supports an Antibody Program, operated by Leidos Biomedical Research, Inc (Leidos Biomed), that comprehensively characterizes affinity reagents for cancer research via the Leidos Biomed Antibody Characterization Laboratory (ACL) located at the Frederick National Laboratory for Cancer Research (FNLCR) in Frederick, MD. Within the Leidos Biomed ACL, a Proteome Characterization Laboratory (PCL) was established for comprehensive Mass Spectrometry (MS)-based proteomic characterization (global- and phospho-proteomes) and targeted (fit-for-purpose) assays. This Task Order (TO) aims not only to expand both the number of assays analyzed by the Leidos Biomed PCL, but also broadens the capabilities with method development of additional Post Translational Modifications (PTMs), fit for purpose antibodies for application such as iMRM and custom assay development. The Leidos Biomed PCL will develop and implement standardized proteomic measurements (comprehensive and targeted) for projects within CPTAC/DCTD. The Leidos Biomed PCL is equipped with two state-of-art mass spectrometers to provide the best sensitivity and accuracy for protein and peptide analysis and benchmarked for proteomic competency in coordination with CPTAC Proteome Characterization Centers (PCCs). The Leidos Biomed PCL will be available for the NCI research community to enhance translational cancer research, with priority given to CPTAC and other DCTD programs.