CEBPB and infection: Further connecting demand-adapted hematopoiesis and trained immunity is the transcription factor CCAAT/enhancer binding protein beta (C/EBPβ), a central regulator of emergency granulopoiesis (EG; the production of in-demand neutrophils following infection) that has recently been shown to also control the epigenetic reprogramming of HSPCs during trained immunity (8–11).