Therefore, using a well-established retinoic acid (RA)-induced fetal rat model of MMC [20,21], the objective of this study was to determine whether AF levels of neurocan and/or phosphacan are elevated in affected fetuses compared to normal age-matched controls at various points of gestation, particularly in early development, and whether elevated levels of neurocan and phosphacan may constitute potential biomarkers for open NTDs. Here, PTPRZ1 is linked to atrial fibrillation.