FTCD and hepatocellular carcinoma: Regarding MTHFS (methenyltetrahydrofolate synthetase) and FTCD (formimidoyltransferase cyclodeaminase), both genes participate in the metabolism of cofactors and vitamins and are downregulated in HCC with a higher tumor stage (Matakidou et al., 2007; Wu et al., 2009; Love et al., 2012; Kanarek et al., 2018) (Supplementary Figure S4A).