STAT3 and hydrops fetalis: Six brain regions of HF animals revealed a >20% increase in basal (saline-injected) pSTAT3 staining compared to LF mice (CO, PM, SNc, ARH, PSV, and VMH), with the ARH (+62%), PSV (+83%), and VMH (90%) displaying the largest increases in basal STAT3 phosphorylation (Fig 4 and S3 Fig).