More recent data suggest a relationship between FGF23 genetic polymorphism and renin-angiotensin-aldosterone system and FGF23 proinflammatory state, nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 dysregulation, cytokine storm, the severity of COVID-19, and a multisystem inflammatory syndrome in children (MIS-C) with cardiac and/or enteric affliction [29]. Here, FGF23 is linked to COVID-19–associated multisystem inflammatory syndrome in children.