NNMT and cancer: NNMT-mediated CD44 mRNA m6A methylation produces a CD44v3 splice variant, while MNA stabilizes CD44 protein by inhibiting the ubiquitin-mediated degradation.404 Furthermore, NNMT depletion elevates the NAD(H)+ levels that result in an enhanced expression of sirtuin target genes and a reduced H3K9Ac.405 Therefore, NNMT acts as a crucial metabolic modulator of epigenetic modification, promoting the migration, invasion, proliferation and survival of cancer cells.