| PIS | preinfarction syndrome; primary immunodeficiency syndrome; Provisional International Standard |
|---|---|
| SCID | severe combined immunodeficiency [syndrome]; soft copy image display; Structured Clinical Interview ... |
| SCIDS | severe combined immunodeficiency syndrome |
| SCIDX | severe combined immunodeficiency disease, X-linked |
| SIV | simian immunodeficiency virus; Sprague-Dawley-Ivanovas [rat] |