FIGURE 2.

Factors contributing to probability of signal detection. (A) Tumors release mutant genomic and epigenomic cfDNA into the circulation. Normal cell types from the surrounding microenvironment and other somatic cells also release cfDNA into the circulation that can be identified through cell-type specific epigenetic markers. Combining tumor cell- and normal host cell-derived signals can increase target abundance in the circulation to increase sensitivity, while maintaining specificity. (B) Target abundance, sequencing depth, and breadth of genomic regions assayed are factors that determine signal detection probability in the circulation of cancer patients. (C) Relative abundance of cfDNA populations and associated specificity.