In this episode of “Lab Medicine Rounds,” host Justin Kreuter, M.D., speaks with Jansen Seheult, M.B., B.Ch., B.A.O., M.D., assistant professor of laboratory medicine and pathology in the Division of Hematopathology, to discuss heterophile antibodies and HIL, which are considered by some to be analytical errors and by others to reflect patient-related pre-analytical variables. Timestamps:00:00 Introduction00:40 Role of pre-analytical variables for coagulation testing03:25 Common pre-analytical variables to be aware of07:49 Medical community collaboration to mitigate patient-related issues11:51  Share about an intervention that was tried and how that worked out14:10 Future of coagulation testing16:34 Outro