A, All biomarkers selected at least 50% of the bootstrapped least absolute shrinkage and selection operator models. B, The 5 most selected biomarkers by bootstrapped least absolute shrinkage and selection operator samples. A set of 9 biomarkers at baseline, day 2, and day 4 remained significant in multivariable analyses after adjustment for hypoxic ischemic encephalopathy severity, treatment assignment, and site. BDNF indicates brain-derived neurotrophic factor; GFAP, glial fibrillary acidic protein; ICAM-1, intercellular adhesion molecule 1; IL, interleukin; MCP, monocyte chemoattractant protein; MIP, macrophage inflammatory protein; NGB, neuroregulin-1-b-1; NSE, neuron-specific enolase; s100b, S100 calcium-binding protein B; TNF-α, tumor necrosis factor–α; UCHL1, ubiquitin carboxy-terminal hydrolase-L1; VCAM, vascular cell adhesion molecule; VEGF, vascular endothelial growth factor.