Moreover, the methyltransferase DOT1L is essential for H3K79 methylation.[83] It has been shown to mediate H3K79me3 dysregulation on the MTDH Wt/Δ7 promoter, thereby increasing transcription in TNBC; depletion of DOT1L abrogates this effect.[84] Our findings consistently indicate that MTA‐driven demethylation of H3K79me1 relies on the inhibition of DOT1L activity, thereby mitigating Cd‐driven BC progression. The gene discussed is DOT1L; the disease is breast cancer.