The evaluated aspects and patient populations varied, for example, Rampton et al. [16] examined the effects of oral ferrous sulfate on various factors including hemoglobin response, hemoglobin levels, iron status markers (transferrin saturation and ferritin), disease activity indices (Harvey-Bradshaw Index, Simple Colitis Clinical Activity Index), C-reactive protein, fecal calprotectin, and psychometric scores. The gene discussed is CRP; the disease is colitis.