Of these 90 reports, 84 were excluded for being in vitro studies (n = 28), lacking information on methemoglobin in malaria (n = 15), being animal studies (n = 14), assessing methemoglobin levels after treatment (n = 8), and for several other specific reasons such as being reviews, assay developments, computational models, case reports or series, meta-analyses, conference abstracts, or having data that were not extractable or only featured methemoglobin in malaria without a comparison group., Google Scholar provided four studies in addition to the main databases. Here, HBG2 is linked to malaria.