APOBEC3B and breast cancer: For instance, A3B mRNA levels across primary breast cancer associated strongly with expression levels of MELK and FOXM1 (Figure 2A), which both have well-described E2F-dependent repression mechanisms (Litovchick et al., 2007; Müller et al., 2017; Müller et al., 2014; Verlinden et al., 2005).