| NOS | network operating system; nitric oxide synthetase; non-organ-specific; not on staff; not otherwise s... |
|---|---|
| OLAS | oligoisoadenylate synthetase |
| PAIS | partial androgen insensitivity syndrome; phosphoribosylaminoimidazole synthetase; psychosocial adjus... |
| PFGS | phosphoribosyl formylglycinamide synthetase |
| PGS | peristent gross splenomegaly; Pettigrew syndrome; plant growth substance; postsurgical gastroparesis... |