SLPI and bacterial urinary tract infection: While AMPs including cathelicidin (29, –, 31), defensins (32, –, 35), ribonucleases (36, –, 39), and serpins (24), have been studied in the context of UTI, little is known about the roles and functions of the well-characterized AMP secretory leukocyte protease inhibitor (SLPI) which is also found in the urogenital tract (40, 41).