In the skeletal muscle of C26 tumor‐bearing mice, we found a significant reduction of mitochondrial iron and total heme content (Fig 3A and B), as well as upregulated levels of mitochondrial iron importer mitoferrin 2 (MFRN2) and of the rate‐limiting enzyme of heme synthesis aminolevulinic acid synthase 2 (ALAS2) (Fig 3C and D) (Barman‐Aksozen et al,2019). The gene discussed is ALAS2; the disease is neoplasm.