Fig.Figure 1(A-B) Hemoglobin (A) and hematocrit (B) levels of healthy subjects and cachectic cancer patients presenting a body weight loss superior to 10% of initial body weight (19 healthy subjects, 17 cachectic patients). Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (C) TFR1 mRNA levels in muscle biopsies from cancer-patients of late stage cachexia (19 healthy subjects, 17 cachectic patients with at least 10% total body weight loss) Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (D) Gastrocnemius weight in mice subjected to iron deprivation by feeding with an iron deficient diet (IDD) combined to a phlebotomy (PHL) (n=5-6); Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (E) TFR1 mRNA levels in the liver of mice subjected to iron deprivation by feeding with an iron deficient diet (IDD) combined to a phlebotomy (PHL) (n=5-6); Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (F) TFR1 mRNA levels in the gastrocnemius of mice subjected to iron deprivation by feeding with an iron deficient diet (IDD) combined to a phlebotomy (PHL) (n=5-6) Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (G) Cross-sectional area of skeletal muscle fiber transfected with shSCR (scramble) and shTFR1 (n=3-4) and representative picture of a shTFR1 transfected fiber. Scale bar=50µm. (H) Cross-sectional area of skeletal muscle fibers transfected with TFR-pHuji (n=4) and representative picture of a TFR-pHuji transfected fiber. Scale bar=50µm. Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (I-J) Diameter of TfR1 (I) or NCOA4 (J) knocked down C2C12 myotubes at day 3 post-transfection (n=7 and n=3 respectively). Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (K) Diameter of C2C12 myotubes after 48h treatment with Deferoxamine 100µM (DFO), bathophenanthroline disulfonate 100µM (BPS), or apo-transferrin (Apo-Tf). Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. (L) Reprensentative pictures and diameter measurements of human myoblast-derived myotubes after 48h treatment with DFO 100µM (n=3). Scale bar=50µm. Data information: For all data, n represents the number of biological replicates. Statistical significance was calculated by unpaired, two-tailed Student's T-test. Data are mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.