In 1991, Wisconsin researchers adapted this DNA isolation method to detect CFTR c.1521_1523delCTT (also-known-as F508del), the most common variant associated with cystic fibrosis (CF), in a randomized clinical trial for NBS for CF in which NBS specimens with elevated immunoreactive trypsinogen (IRT), a biomarker elevated in newborns with CF, underwent F508del analysis [3]. The gene discussed is CFTR; the disease is cystic fibrosis.