Validation is a dish oft served cold

In this issue of Blood, Triot et al describe a novel genetic subtype of severe congenital neutropenia (SCN) characterized by inherited, biallelic loss-of-function mutations in the granulocyte -colony-stimulating factor (G-CSF) receptor gene, CSF3R.¹ These findings expand the spectrum of pathogenic CSF3R mutations in humans and provide long overdue validation of mouse models generated in the 1990s.