Functional immunological assays

Abstract

This special issue is focused on functional immunological assays. As such, the definition of a functional assay is in order. There is in fact no universal consensus on the definition of functional assays; it can mean different things to different people. Here we will define them as assays that evaluate what a particular molecule or cell can do as opposed to the tests that assess the presence or absence of those cells and molecules. While establishing the decrease or absence of a normal component, either cell or molecule, is often an indication of pathology, the presence of normal numbers of the cell, or amounts of the molecule in question does not always mean the absence of pathology.