TFRC and nutritional disorder: Iron deficiency has been reported to reduce the levels and/or activities of key metabolic iron-containing enzymes, in cell lines, in the hearts of mice with impaired cardiac iron uptake (cardiac-specific TfR1 knockouts) and in the hearts of mice fed an iron-deficient diet (Dallman, 1986; Dhur et al., 1989; Xu et al., 2015; Oexle et al., 1999).