Variables modifying expression and upstream regulators of Arhgap39/Porf-2
| Developmental stage (rat brain) |
| Age (rat brain and testes) |
| Sex (rat brain) |
| Brain region (rat) |
| Gonadal hormones, including estradiol and progesterone (rat brain) |
| Pituitary factors (rat brain and testes) |
| Epigenetic mechanisms such as miRNAs |
| Insulin and IGF-1 (FRTL-5 cells) |
| Type 2 diabetes (Zucker rat kidney) |
| Obesity (human liver) |