Detailed Instructions: In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.
Q: Scatchard analysis of the binding data revealed a single class of high - affinity binding on human B cells with approximately 2600 binding sites per cell and an apparent dissociation constant ( K ( D ) ) of about 0 . 1 nM .
A:
binding sites