Of note, DOT1L has been found upregulated in breast cancer stem cells (CSC), suggesting that this enzyme plays a critical role in breast tumor initiation promoting tumorigenic and self-renewal activity of CSCs populations (Cho et al., 2015), a finding also confirmed by Oktyabri et al., who elucidated an important role of lysine methyltransferase in determining the stem cell-like properties of breast cancer cells regulating the expression of BCAT1, an enzyme involved in the amino-acid metabolism (Oktyabri et al., 2016). Here, DOT1L is linked to breast cancer.