SIT1 and hyperinsulinemic hypoglycemia, familial, 4: Upon differentiation into mature macrophages, U937 cells were infected with the wild type, sit1Δ and sit1Δ::SIT1 C. glabrata strains grown under Fe deficiency, with or without a brief exposure to ferrichrome, and yeast CFU quantitated after 18, 24 and 36 hours of co-culture.