During infections, many pathogens forage iron from human hemoglobin (Hb), as it contains ∼ 75–80% of the human body’s total iron content in the form of heme (iron-protoporphyrin IX) (Parrow et al., 2013; Contreras et al., 2014; Wandersman and Delepelaire, 2014; Ma et al., 2015; Sheldon and Heinrichs, 2015; Choby and Skaar, 2016; Sheldon et al., 2016; Huang and Wilks, 2017; Conroy et al., 2019). The gene discussed is GSTM1; the disease is infection.