MTHFR and mucositis: Similarly, the substantial changes of pooled OR (95% CI) were detected in the following comparisons of MTHFR (rs1801133): the result of hepatotoxicity under recessive and allelic models after excluding Chang 2021 (Chang et al., 2021) or Suthandiram 2014 (Suthandiram et al., 2014); the renal toxicity under recessive and allelic models after excluding Chang 2021 (Chang et al., 2021); the mucositis under dominant and allelic models after excluding Faganel 2011 (Faganel Kotnik et al., 2011); and the mucositis under the recessive model after excluding Suthandiram 2014 (Suthandiram et al., 2014).