TFRC and B-cell chronic lymphocytic leukemia: Iron is essential for B-cell function, as deletion of the transferrin receptor TFRC/CD71 in B cells results in substantial functional impairments,41 including defects in proliferation and antibody production.42 While most circulating CLL cells are quiescent, those residing in lymphoid niches proliferate actively.43 Within these protective niches, CLL cells are shielded from intrinsic and extrinsic stressors, including therapy-induced cytotoxicity.7,8,14 Accordingly, we observed that stromal interactions enhanced the resilience of CLL cells to ferroptosis.