Figure 1.

Bulk measurements include irrelevant cell populations that introduce noise, and reduce the power to detect cells of interest. If a population of cells, defined by the phenotype A⁻ B⁺ C⁺ D⁻, correlates strongly with disease or immunity, then assays with fewer than four markers include irrelevant populations that introduce noise into the assay. Note that the measurement of too many may also reduce power, unless the additional markers are excluded from analysis.