A 15-YEAR-OLD WHITE BOY was diagnosed as having cystic fibrosis (CF) at age 4 years after symptoms of projectile vomiting, bulky stools, and anemia. Of 32 alleles tested, his genotype is N1303K/unidentified allele. He had multiple hospital admissions through age 2 years and only 4 until 1991, age 7 years. In 1994, he had a biliary tract obstruction requiring endoscopic intervention. In February 1991, he was diagnosed as having diabetes mellitus (DM) glucose intolerance. Subsequently, a therapeutic regimen of glipizide and a diet with no concentrated sweets was begun. Later that year, during a hospitalization, he had sustained elevated serum glucose levels while receiving prednisone. His hemoglobin A1c level was 6.1 mg/dL. Urine protein was monitored regularly from 1991 through 1994, and traces began to appear in June 1992 but did not reach high levels until 1994. At hospital admission, he was receiving glipizide by mouth, 5 mg every morning and 10 mg every evening. He had a history of noncompliance with daily glucose monitoring, and many spot glucose measurements were taken, measuring in the 16.7-mmol/L (300-mg/dL) range. After urine protein levels reached 1528 mg/24 h in August 1994, a renal biopsy was performed. Hemoglobin A1c levels were 12.3 in February 1994 and 8.2 in August 1994. The patient never had clinical symptoms of glomerulonephritis (Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5).