Task: Named Entity Recognition
Input (English):  The IR4 ORF exhibits significant homology to the immediate - early gene US1 ( ICP22 ) of herpes simplex virus type 1 and to the ICP22 homologs of varicella - zoster virus ( ORF63 ) , pseudorabies virus ( RSp40 ) , and equine herpesvirus 4 ( ORF4 ) .
Output (English): early gene