TfR is induced during pregnancy, in response to iron deficiency; it is rapidly transcytosed to the apical membrane of syncytiotrophoblasts (Gruper et al., 2005), as demonstrated in rodent (Gambling et al., 2001; Cornock et al., 2013) and human studies (Li et al., 2012a) of maternal iron deficiency. Here, TFRC is linked to Iron deficiency anemia.