PTGER1 and neoplasm: At 35 days, nandrolone upregulated selected transcription factors by 1.5- to 2.8-fold, including early response genes (Egr1, Egr2, and Egr3), the human immunodeficiency virus type I enhancer binding protein 1 (HIV EP1), and Nupr1, a tumor suppressor that regulates transcription and has been associated with cardiac muscle hypertrophy [30] (Table 2).