The detection of cancer biomarkers in body fluids, referred to as "Liquid Biopsy", has become a cutting-edge technology that has the potential to non-invasively screen and diagnose cancer at early stage, monitor tumor progression, and evaluate therapy responses. The molecular profiles gathered from circulating tumor DNA (ctDNA) such as gene alteration and DNA methylation can be further complemented with the analysis of circulating tumor cells (CTCs), RNA, proteins, and exosomes. NIST has collaborations with the National Cancer Institute laboratories that are specialized in cancer biomarker discovery and characterization. Potential projects include the effect of altered nucleosome positioning and aberrant DNA methylation on the early detection of cancer. Nucleosome positioning and DNA methylation profiling can potentially be used for quantitative estimation of tumor burden and tissue-of-origin mapping in liquid biopsies. Additional projects include the application of PCR-free electrochemical and other emerging detection methods for the sensitive and selective measurements of cancer biomarkers in liquid biopsies. Applicants with experience and interests in the development of digital PCR, next-generation sequencing methods, other PCR-free methods or bioinformatic analysis for the sensitive measurement of rare allele genetic alterations or epigenetics alterations are encouraged to apply.