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.

The B - cell - type specificity of the immunoglobulin ( Ig ) heavy - chain and light - chain promoters is mediated by an octanucleotide ( OCTA ) element , ATGCAAAT , that is also a functional component of other RNA polymerase II promoters , such as snRNA and histone H2B promoters .
RNA polymerase II