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Number of analytes
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Single analyte relative to biological functions (small molecules or macromolecules)
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Multiple analytes with complex functional relationships between tumor and immune system
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Category of measurement
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Absolute quantitation
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Quasi-quantitative, relative-quantitative or qualitative. Qantification is available for specific assays
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Reference material
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Available
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Not available, limited availability or available - depends on the assay
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Linearity of analyte(s)
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Known
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Unknown or do not demonstrate linearity, often unknown dynamic ranges, or dynamic range can be established-depends on the assay
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Limit of detection (LOD)
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Available
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Not quantifiable or LOD available - depends on the assay
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Sample processing
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Extraction required for small molecules; Direct measurement in biological matrix without sample pretreatment
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Single cells or specific cell types frequently required for blood-based assay; tissue processing required for FFPE samples; tissue processing required for DNA and RNA
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Function assessment
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Not necessary - a determinant of the static molecular status
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Functional assays often require ex vivo response to stimuli
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Time for archived clinical samples analysis
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Relatively short, <1 yr
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Often long >1 yr; Depends on the stability of biomarker/assay
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