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.
Input: On the basis of experiments with mutant virus and transfection with isolated genes , the herpes simplex virus immediate - early gene product ICP4 is known to positively regulate the transcription of viral early and late genes and negatively regulate expression from its own promoter .
Output:
early gene