| HAT | Histone acetyl transferase |
|---|---|
| HGPRT | Hypoxanthine Guanine Phosphoribosyl Transferase |
| HPRT | Hypoxanthine phosphoribosyl transferase |
| HGPRTase | Hypoxanthine-guanine phosphoribosyl transferase |
| HGXPRTase | Hypoxanthine-guanine-xanthine phosphoribosyl transferase |