Duodenal expression levels of Pfn2 mRNA in mice with intestinal IRP1 and IRP2 depletion in adult stage. IRP1 and IRP2 deficiency was obtained using the Cre/LoxP technology in a tamoxifen-inducible system in the intestinal mucosa. Adult animals carrying floxed IRP alleles plus the Cre-ERT (XerC recombinase fused to an estrogen receptor tamoxifen-activated) transgene were given tamoxifen (1 mg intraperitoneally per animal per day on 5 consecutive days) to trigger IRP ablation in the intestine. Mice were euthanized 5 weeks after the last tamoxifen injection and Pfn2 mRNA levels (A) as well as Tfrc mRNA levels (B) were assesed by qPCR. Control mice (blue bars) were WT mice treated with oil (no CRE oil) or tamoxifen (no CRE tamoxifen), or CRE-expressing mice receiving the vehicle only (CRE oil). Tfrc mRNA expression was assessed as a molecular signature of IRP deficiency. The histograms represent mRNA levels after calibration to β-actin and normalization to the “no Cre oil” control. P values were determined by unpaired 2-tailed Student t test, **P ≤ .01, ***P ≤ .001.