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.

 We describe a novel and potentially important mechanism of nitric oxide signaling - through direct activation of guanine nucleotide - binding proteins ( G proteins ) .
G proteins

 Transcription factor B - cell - specific activator protein ( BSAP ) is differentially expressed in B cells and in subsets of B - cell lymphomas .
Transcription factor

 Inclusion of the sequences between - 4 and + 52 enhanced promoter activity ; this was primarily because of an Sp1 recognition site at + 9 / + 15 .

Sp1 recognition site