TFRC and sickle cell disease: Soluble transferrin receptor (sTfR) is only mildly increased during the inflammatory response [11], but its utility is complicated in African populations since it is upregulated by malaria, even in asymptomatic infection, and by hemolytic conditions such as sickle cell disease, thalassemia, and glucose-6-phosphate dehydrogenase (G6PD) deficiency.