Cell-associated differentiation antigens (CDs) are functional cell surface proteins or receptors that can be measured in situ.
A) In normal individuals the concentration of these molecules in serum is always low.
B) Detecting these soluble molecules may help in the management of disease.
C) Thousands of CDs have been characterized.
D) All of the above are true.
E) None of the above are true.
6
An immunoglobulin is a