Provenzi L, Fumagalli M, di Minico GS, et al. - In 4.5-year-old preterm children vs full-term matched counterparts, researchers intended to determine if there is a connection between the pain-related increase in serotonin transporter gene (SLC6A4) methylation and emotional dysregulation. From October 2011 to December 2017, preterm (n = 29) and full-term (n = 26) children recruited from two Italian hospitals were followed-up. In response to emotional stress, preterm children (mean age = 4.5, range = 4.3 – 4.8) exhibited greater anger display vs full-term controls (mean age = 4.5, range = 4.4 – 4.9). Controlling the occurrence of adverse life events from discharge to 4.5 years and SLC6A4 methylation at birth, CpG-specific SLC6A4 methylation in the neonatal period predicted greater display of anger in preterm children but not in full-term children. Such outcomes help to highlight how epigenetic regulation of the serotonin transporter gene in response to exposure to NICU pain contributes to long-lasting anger regulation programming in preterm children.