Absence of PCFT decreases systemic folate content and leads to iron and homocysteine buildup. (A) Concentration of folate, iron, heme, and tHcy in the indicated tissues was determined in 4- to 6-week-old mice of indicated genotype. Data are presented as in Figure 2; n = 12 mice in each cohort. (B) Gomori iron staining of liver sections (original magnification 40×/0.75 NA dry objective). Iron is detected in periportal hepatocytes of PCFT^−/− mice mainly as fine cytoplasmic stippling and rarely as cytoplasmic granules on a diffuse light blue cytoplasmic background. Iron is not detected by Gomori staining in liver sections from WT animals.