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.

Example input: Sox - 4 is important for very early B - cell differentiation , while TCF - 1 / LEF - 1 play a crucial role in early thymocyte development
Example output: TCF - 1
Example explanation: The gene, TCF - 1 has been tagged as protein since it plays a crucial role in early thymocyte development.
Q: Taken together with prior in vivo transcription studies , these results suggest that the biological activities of p65 and p50 homodimers are independently regulated , thereby providing an integrated and flexible control mechanism for the rapid activation and repression of NF - kappa B / Rel - directed gene expression .
A:
p50 homodimers