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.

Antisense HIF - 1alpha monotherapy resulted in the complete and permanent rejection of small ( 0 . 1 cm in diameter ) EL - 4 tumors , which is unusual for an anti - angiogenic agent where transient suppression of tumor growth is the norm .
HIF - 1alpha