Date: JUN.8.2021 Summary https://doi.org/10.1093/clinchem/hvab031 A 25-day-old boy, born at term with an uneventful birth history, presented to the emergency department for choking and rapid breathing postfeeding. He was admitted and treated for aspiration pneumonia with C-penicillin and gentamicin. Prior to this, he was incidentally noted to have a systolic murmur by a private pediatrician. Echocardiography during this admission revealed perimembranous ventricular septal defect (VSD) in failure. Complete Article Commentary: S.C. Kazmierczak Commentary: M.H. Wojcik