This indicates that the labile iron that is generated from the degradation of H ferritin or mediated by TFRC is involved in the capacity to form spheres.118 H ferritin knock‐down inhibited glioblastoma CSC growth and impaired a stem‐like phenotype in breast cancer cells.115, 119 These studies showed that CSCs are iron‐rich and iron‐dependent. Here, FTH1 is linked to breast carcinoma.