FTH1 and nutritional disorder: In addition, qPCR and Western blot analysis also revealed reduced expression of the iron storage molecule FT—detected by ferritin heavy chain 1 (Fth1)—(Figure 6A,C), while expression of the basolateral iron importer transferrin receptor 1 (Tfr1) was increased in whole-body Ptpn2-deficient mouse duodenal IECs vs. Ptpn2-WT or Het duodenal IECs (Figure 6B,D), indicating cellular iron deficiency [26].